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ROBERT

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" Prison calls on dog to sniff out illicit phones

Give the dog a phone: a sniffer dog has been put to work in British prisons with the specific brief of tracking down illicit mobile phones held by inmates.

Murphy, a 15-month-old English springer spaniel, has started work at Norwich Prison in eastern England and will be working at 12 other jails in the region.

Norwich Prison governor James Shanley says their biggest concern is to maintain public protection.

"And we do not want mobile phones to circumvent all the systems set up to provide this," he said.

"If somebody has access to a mobile phone in prison they could potentially contact witnesses, or they could use the phone as a means of escape by arranging for someone to meet them at a certain place.

"Phones can also be used to take photos and could identify staff or other visitors to the prison."

Mr Shanley says about 500 mobile phones have been found in the 12 prisons in the past year.

Murphy, who came from a rescue centre, is believed to be the first mobile phone sniffer dog in Britain's Prison Service. "

http://www.abc.net.au/news/newsitems/200609/s1745690.htm


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" Cloning without stem cells works  

US scientists say stem cells are not necessary for cloning and other cells may even be better candidates.

The Pittsburgh University team created two baby mice from a fully matured blood cell that itself is incapable of making more of its own kind.

It had been thought only immature stem cells, which can become many types of other cell, were capable of doing this.

A UK expert said the Nature Genetics study disproved the idea that only immature cells were of use for cloning.

Alternative routes

Somatic cell nuclear transfer (SCNT) - the scientific term for cloning - is creating an embryo by taking the nucleus, which houses the genetic material of a cell, from one cell and putting it into an unfertilised egg that has had its own genetic material removed.

The resulting embryo is then an exact genetic copy of the cell from the animal or person that donated the nucleus.

 TYPES OF STEM CELLS
Embryonic stem cells - derived from embryos that develop from eggs that have been fertilized
Adult stem cells - immature cells that have yet to fully develop, and found in tissue and organs

Stem cells are still at an early stage of development, and retain the potential to turn into many different types of cell that make up tissues and organs, which is why experts have heralded their promise for treating a variety of genetic diseases.

But experiments using adult stem cells taken from mature tissue to make early stage embryos have yielded disappointing results, with success rates of 1-5%.

Dr Tao Cheng and colleagues tested whether a fully matured type of white blood cell, called a granulocyte, could propagate early embryos.

Not only was this successful, the granulocyte was far better at this than its immature ancestor cells destined to become granulocytes. "

http://news.bbc.co.uk/1/hi/health/5391220.stm
 
« Last Edit: 03/10/2006 16:18:04 by ROBERT »

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" Spider Silk Could Repair Human Ligaments
By Charles Q. Choi
Special to LiveScience
posted: 13 October 2006
10:29 am ET  

Spider web silk, the strongest natural fiber known, could possess untapped medical potential in artificial tendons or for regenerating ligaments, scientists now say.

A body of folklore dating back at least 2,000 years tells of the potential medical value of spider webs in fighting infections, stemming bleeding and healing wounds, explained molecular biologist Randolph Lewis at the University of Wyoming in Laramie. Spider webs have even found a place in Shakespeare's play "A Midsummer Night's Dream," where the character dubbed Bottom noted, "Good Master Cobweb: if I cut my finger, I shall make bold with you."

While research has found no evidence so far that spider webs can kill germs, Lewis explained, studies on animals have revealed that spider silk triggers little if any immune responses, which cause rejection of medical implants.

So his lab and others are spinning spider silks into fibers that they hope might be useful in medicine.

Lewis said researchers at Tufts University in Medford, Mass., have found that spider webs could be used as scaffolds for regenerating ligaments damaged in one of the world's most common knee injuries—ruptured anterior cruciate ligaments, or ACLs. "We're also looking at spider silk in artificial tendons," he said.

Scientists are also developing spider silk to make exceptionally fine sutures for stitching up surgeries or wounds to nerves or eyes, to potentially help them heal without scarring.

"Right now we haven't even optimized the silks we've produced yet, and we're in the ballpark of the material properties you'd want for artificial tendons and ligaments," Lewis told LiveScience.

To mass-produce spider silk, Lewis said "our lab is pursuing the production of spider silk in alfalfa." Other researchers are experimenting with producing spider silk proteins in goat milk. Scientists generate these proteins outside spiders by inserting the genes for them into target cells.

Lewis summed up current work in the latest issue of the journal Chemical Reviews. "

http://www.livescience.com/humanbiology/061013_spider_medicine.html

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" Doubt cast on lunar ice deposits  

By Paul Rincon
Science Reporter, BBC News, Wednesday, 18 October 2006.
 
Nasa hopes to return humans to the Moon by 2020
Hopes that the Moon's south pole has significant water ice deposits that could be used to set up a lunar base appear to be unfounded, a study says.

Hypothesised deposits of lunar water-ice have figured in Nasa's planning for future Moon landings.

This resource would be invaluable for supplying bases and making fuel for propelling spacecraft beyond the Moon.

The study in Nature journal suggests radar echoes thought to be from frozen water could be from rocky debris.

The simplest explanation is that we're looking at a signature due to [impact debris] from the crater and not some strange signature due to water ice

Jean-Luc Margot, Cornell University
The first evidence for water-ice deposits came from radar observations made by the US Moon orbiter Clementine, launched in 1994.

According to mission scientists, values for a radar signature called the "circular polarisation ratio (CPR)" indicated frozen water below the dust in craters near the lunar south pole that were shaded from the Sun.

The Clementine researchers also admitted that this radar signature could be created by echoes from rough terrain and walls of impact craters.

In the latest study, Donald Campbell of Cornell University in Ithaca, New York, and colleagues suggest the latter explanation is the more likely. "

http://news.bbc.co.uk/1/hi/sci/tech/6061984.stm

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" Stem cell insulin offers hope to type 1 diabetics

28 October 2006

INSULIN-secreting cells have been created from human embryonic stem cells for the first time, raising hopes of a limitless supply of cells that could be transplanted into people with type 1 diabetes.

Emmanuel Baetge and his colleagues at Novocell in San Diego, California, used a cocktail of chemicals to coax the stem cells to form pancreatic cells (Nature Biotechnology, DOI: 10.1038/nbt1259). The cells produce as much insulin as normal pancreatic islet cells, but unlike adult islet cells, this doesn't appear to be regulated by sugar levels. Baetge is confident they can overcome this problem.

If they succeed, the company has also developed a way to coat the cells in a polymer called polyethylene glycol, which would prevent them from being rejected by the recipient's immune system, while allowing sugar, insulin and other signalling molecules to filter in and out. "

http://www.newscientist.com/channel/health/mg19225754.500-stem-cell-insulin-offers-hope-to-type-1-diabetics.html




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Quote

Dolphin May Have 'Remains' of Legs

Possible Evidence Ocean Mammals Lived on Land
In this photo released by Taiji Whale Museum, divers hold a bottlenose dolphin which has an extra set of human palm-sized fins near its tail in Taiji, Wakayama prefecture (state) in western Japan, on Saturday November 4, 2006. Japanese researchers said Sunday that the could be the remains of back legs, providing further evidence that ocean-dwelling mammals once lived on land. (AP Photo/Taiji Whale Museum)

By HIROKO TABUCHI

TOKYO Nov 6, 2006 (AP)— Japanese researchers said Sunday that a bottlenose dolphin captured last month has an extra set of fins that could be the remains of hind legs, a discovery that may provide further evidence that ocean-dwelling mammals once lived on land.

Fishermen captured the four-finned dolphin alive off the coast of Wakayama prefecture (state) in western Japan on Oct. 28, and alerted the nearby Taiji Whaling Museum, according to museum director Katsuki Hayashi.

Fossil remains show dolphins and whales were four-footed land animals about 50 million years ago and share the same common ancestor as hippos and deer. Scientists believe they later transitioned to an aquatic lifestyle and their hind limbs disappeared.

Whale and dolphin fetuses also show signs of hind protrusions but these generally disappear before birth.

Though odd-shaped protrusions have been found near the tails of dolphins and whales captured in the past, researchers say this was the first time one had been found with well-developed, symmetrical fins, Hayashi said.

"I believe the fins may be remains from the time when dolphins' ancient ancestors lived on land … this is an unprecedented discovery," Seiji Osumi, an adviser at Tokyo's Institute of Cetacean Research, said at a news conference televised Sunday.

The second set of fins much smaller than the dolphin's front fins are about the size of human hands and protrude from near the tail on the dolphin's underside. The dolphin measures 8.92 feet and is about five years old, according to the museum.

Hayashi said he could not tell from watching the dolphin swim in a musuem tank whether it used its back fins to maneuver.

A freak mutation may have caused the ancient trait to reassert itself, Osumi said. The dolphin will be kept at the Taiji museum to undergo X-ray and DNA tests, according to Hayashi.

http://abcnews.go.com/Technology/wireStory?id=2629683

"Dolphin with extra fins" sounds like a dish on a Japanese menu  [:)]
« Last Edit: 13/11/2006 16:45:35 by ROBERT »

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'Nymph of the sea' reveals remarkable brood

The scientists discovered the mother complete with her brood of some 20 eggs and 2 possible juveniles inside, together with other details of her soft part anatomy including legs and eyes.

The research team consisted of David Siveter from the University of Leicester, Derek Siveter from Oxford, Mark Sutton from Imperial College London and Derek Briggs from Yale.

The team has made a digital image of the fossil - an ostracod (a relative of the shrimps) - which is preserved exceptionally in volcanic ash rocks in Herefordshire. Their findings are published on line in the Proceedings of the Royal Society.

Professor David Siveter, of the Department of Geology at the University of Leicester, said : "Ostracods are common, pin-head sized crustaceans known from thousands of living species in garden ponds to oceans and from countless fossil shells up to 500 million years old; however, their fossilized soft-parts are exceedingly rare.

"Supposed examples of fossil invertebrate eggs are also few. The fossil we have found contains soft-part anatomy such as legs and eyes and also includes about twenty eggs, each about half a millimetre in size, and two possible juveniles.

"The fossil has been christened Nymphatelina gravida, meaning' a pregnant young woman of the sea'. This remarkable discovery provides an unequivocal and unique view of parental brood care in the invertebrate fossil record, it allows gender to be determined in an animal as old as the Silurian period of geological time, and indicates a remarkably conserved egg brooding reproductive strategy."

SOURCE: EUREKA ALERT
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Dad inspired 'Jurassic Park,' son inspires 'Jurassic Poop'
Book reveals how ancient poop has the inside scoop on US past


November 15th, 2006 -- Twenty-five years ago American entomologist George Poinar's work on ancient insects in amber inspired Michael Crichton's futuristic thriller Jurassic Park. Now son Hendrik Poinar's groundbreaking work has inspired the world's first book on the science of fossil feces, Jurassic Poop.

The new children's book by Canadian science writer Jacob Berkowitz reveals that America not only has the world's largest heap of ancient human leavings but that the study of coprolites, or fossil feces, is literally re-writing American history, including who attended the first Thanksgiving.

Developed completely from original scientific sources, Jurassic Poop is the first comprehensive book on coprolites, full of facts and stories that are intriguing to readers five to 100.

"When I saw my first coprolite ten years ago, I thought no way, how could something as soft as poop fossilize?," says Berkowitz. "But coprolites are found on every continent and from every geological time period. There's literally tons of fossil poop out there, and it's now recognized as priceless for helping scientists piece together the puzzle of ancient life."

Jurassic Poop profiles the work of Hendrik Poinar, a professor at McMaster University, in Hamilton, Canada. He was the first ever to extract DNA from ancient feces.

While his father's work in teasing DNA from insects in amber benefited from the revolutionary genetic technological advances of the 1980s -- particularly the invention of the polymerase chain reaction (PCR) to duplicate and thereby identify DNA fragments -- Hendrik's benefited from medical advances. The technique used to extract DNA from coprolites uses a chemical developed for the treatment of diabetes-related complications.

"After being pooh-poohed by scientists for decades, coprolites have now been shown to be the best source of ancient DNA, better than bones and teeth," says Berkowitz. Hendrik Poinar is now able to identify not only a pooper's gender, but also critical genetic information that will help to uncover the very origins of modern humans.

Berkowitz says coprolites even have something to say about one of the seminal stories in American history, the arrival of the Mayflower.

The official Mayflower record says that the only animals on board were two dogs. But in the mid-1990s an archaeological excavation of a 17th century Boston privy revealed another story. The Mayflower was infested with at least 20 types of Old World beetles, stow-aways who quickly called America home -- and do to this day.

Jurassic Poop also reveals that more than 1000 human coprolites have been collected from Hinds Cave in the Chihuahuan desert in southwest Texas, making the site the largest human coprolite cache ever found.

The fossilized specimens were deposited by ancient Americans over the course of about 8000 years. The book notes that these human remains are about 95-per cent fibre. That's about 15 times the amount of fibre the average American eats today. Hendrik Poinar is now collaborating with Vaughn Bryant of Texas A&M University to extract genetic information from the Hinds Cave coprolites.


SOURCE: EUREKA ALERT
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Volcanic blast likely killed and preserved juvenile fossil plesiosaur found in Antarctica
Skeleton to be unveiled at US museum December 13


Amid 70-mile-an-hour winds and freezing Antarctic conditions, an American-Argentine research team has recovered the well-preserved fossil skeleton of a juvenile plesiosaur--a marine reptile that swam the waters of the Southern Ocean roughly 70 million years ago.

The fossil remains represent one of the most-complete plesiosaur skeletons ever found and is thought to be the best-articulated fossil skeleton ever recovered from Antarctica. The creature would have inhabited Antarctic waters during a period when the Earth and oceans were far warmer than they are today.

James E. Martin, curator of vertebrate paleontology and coordinator of the paleontology program at the South Dakota School of Mines and Technology's Museum of Geology, announced today the plesiosaur bones will be unveiled at the museum on Dec.13, 2006.

The long-necked, diamond-finned plesiosaurs are probably most familiar as the legendary inhabitants of Scotland's Loch Ness, although scientific evidence indicates the marine carnivores have been extinct for millions of years. But when the creatures were alive, their paddle-like fins would have allowed them to "fly through the water" in a motion very similar to modern-day penguins.

Martin, an expert on fossil marine reptiles, co-led the 2005 expedition to Antarctica that recovered the plesiosaur. Judd Case, of Eastern Washington University, and Marcelo Reguero of the Museo de La Plata, Argentina, were also co- leaders.

The National Science Foundation (NSF) and the Instituto Antártico Argentino, directed by Sergio Marenssi, funded the expedition. The Argentine Air Force provided helicopter support.

NSF manages the U.S Antarctic Program, which coordinates all U.S. research on the southernmost continent. The White House has designated NSF as the lead federal agency for the International Polar Year, a 2-year global research campaign in the polar regions that begins in March 2007.

Preserved by a volcanic blast

After it was prepared in the United States, Martin said, the specimen was discovered tobe the 5-foot-long (1.5 meters) skeleton of a long-necked (elasmosaurid) plesiosaur. An adult specimen could reach over 32 feet (10 meters) in length. Most of the bones of the baby plesiosaur had not developed distinct ends due to the youth of the specimen, he said.

But the animal's stomach area was spectacularly preserved. Stomach ribs (gastralia) span the abdomen, and rather than being long, straight bones like those of most plesiosaurs, these are forked, sometimes into three prongs. Moreover, numerous small, rounded stomach stones (gastroliths) are concentrated within the abdominal cavity, indicating stomach stones were ingested even by juvenile plesiosaurs to help maintain buoyancy or to aid digestion.

The skeleton is nearly perfectly articulated as it would have been in life, but the skull has eroded away from the body. Extreme weather at the excavation site on Vega Island off the Antarctic Peninsula and lack of field time prevented further exploration for the eroded skull.

The researchers speculate volcanism similar to the massive eruption of Mt. St. Helens in Washington in 1980, may have caused the animal's death. Excavation turned up volcanic ash beds layered within the shallow marine sands at the site, and chunks of ash were found with plant material inside. That suggests a major blow-down of trees as was observed when Mt. St. Helens erupted. Either the blast or ash dumped into the ocean, the scientists say, may have caused the baby's demise. Moreover, silica released from the ash allowed spectacular preservation of the skeleton.

High winds, freezing water, hard work

As with the find of a new species of dinosaur Martin and Case made in Antarctica several years ago, the weather and the harsh Antarctic climate made collecting the plesiosaur specimen exceedingly difficult. Weeks of winds exceeding 70 miles an hour hindered the excavation. At the end of the work, icy temperatures turned water to slush before plaster could be mixed to encase the fossil for transportation. The ground was so frozen a digging tool snapped in half during the excavation. Finally, a jackhammer had to be carried up to the site in backpacks along with gasoline, plaster, and water.

The resulting package of plesiosaur remains encased in a protective plaster jacket was too large to carry, so the Argentine air force brought helicopters to the rescue. It took five men to lift the specimen into the chopper, which delivered the cargo to the tent camp on the shores of Herbert Sound. The specimen was later picked up by the Laurence M. Gould, an NSF-chartered research vessel.

At the Museum of Geology, the reptile was prepared by Michelle Pinsdorf and replicated by Shawna Johnson, both master's degree students of paleontology at the South Dakota School of Mines.

A prehistoric nursery

J. Foster Sawyer, of the South Dakota Geological Survey and the School of Mines, found the skeleton while working with Martin at an elevation of 650 feet (200 meters) on Vega Island. Sawyer found vertebrae exposed by wind from the ancient sandy seabed. The bones were embedded in rocks and associated with marine shellfish that suggest the area was a shallow-water marine environment roughly 70 million years ago. Two other partial plesiosaurs were also collected, as well as finds of very advanced shore birds.

Since 1998, expeditions by the American-Argentine team to the area--in part to compare the ancient climates of South Dakota and Antarctica--have secured numerous isolated elements of juvenile plesiosaurs and mosasaurs, a giant marine reptile that looked like an alligator with fins. Martin and his colleagues believe the site may have been a shallow-water area where marine reptiles had their young, and where the young remained until they were of sufficient size and ability to survive in open waters.

Whether plesiosaurs gave live birth has not been proved, but numerous bones and partial skeletons of larger plesiosaurs were found in the same area as the young. Given the long history of plesiosaurs, evolution would have had ample time for them to develop a form of live birth.

The juvenile plesiosaur appears to be related to one discovered in New Zealand in 1874. That plesiosaur was named Mauisaurus and is characterized by a rounded end of the major paddle bone. It was confined to the southern oceans where it existed more than 5 million years.

EUREKAALERT.ORG

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Supercomputer studies Milky Way's halo of dark matter
UC-SANTA CRUZ NEWS RELEASE

Researchers at the University of California, Santa Cruz, have used NASA's most powerful supercomputer to run the largest simulation to date of the formation and evolution of the dark matter halo that envelopes the Milky Way galaxy. Their results show substructures within the halo in unprecedented detail, providing a valuable tool for understanding the evolutionary history of our galaxy.

Every galaxy is surrounded by a halo of mysterious dark matter that can only be detected indirectly by observing its gravitational effects. The invisible halo is much larger and more spherical than the luminous galaxy at its center. Recent computer simulations have shown that the halo is surprisingly clumpy, with relatively dense concentrations of dark matter in gravitationally bound 'subhalos' within the halo. The new study, which has been accepted for publication in the Astrophysical Journal, shows much more extensive substructure than any previous study.

"We find almost 10,000 subhalos, about one order of magnitude more than in any past simulations, and some of our subhalos exhibit 'subsubstructure.' This was expected theoretically, but we have shown it for the first time in a numerical simulation," said Piero Madau, professor of astronomy and astrophysics at UCSC and a coauthor of the paper.

Jurg Diemand, a Hubble postdoctoral fellow at UCSC and first author of the paper, said the new results exacerbate what is known as the "missing satellite problem." The problem is that the clumpiness of the normal matter in and around our galaxy--in the form of dwarf satellite galaxies--does not match the clumpiness of the dark matter seen in the simulation.

"Astronomers keep discovering new dwarf galaxies, but there are still only about 15 or so, compared to about 120 dark matter subhalos of comparable size in our simulation. So which ones host the dwarf galaxies, and why?" Diemand said.

Theoretical models in which star formation is restricted to certain types of dark matter halos--sufficiently massive or early-forming ones--may help to resolve the discrepancy, Madau said.

Although the nature of dark matter remains a mystery, it appears to account for about 82 percent of the matter in the universe. As a result, the evolution of structure in the universe has been driven by the gravitational interactions of dark matter. The "normal" matter that forms gas and stars has fallen into the "gravitational wells" created by clumps of dark matter, giving rise to galaxies in the centers of dark matter halos.

Initially, gravity acted on slight density fluctuations present shortly after the Big Bang to pull together the first clumps of dark matter. These grew into larger and larger clumps through the hierarchical merging of smaller progenitors. This is the process the UCSC researchers simulated on the Columbia supercomputer at the NASA Ames Research Center, one of the fastest computers in the world. The simulation took a couple of months to complete, running on 300 to 400 processors at a time for 320,000 "cpu-hours," Diemand said.

Coauthor Michael Kuhlen, who began working on the project as a graduate student at UCSC and is now at the Institute for Advanced Study in Princeton, said the researchers set the initial conditions based on the most recent results from the Wilkinson Microwave Anisotropy Probe (WMAP) experiment. Released in March, the new WMAP results provide the most detailed picture ever of the infant universe.

The simulation starts at about 50 million years after the Big Bang and calculates the interactions of 234 million particles of dark matter over 13.7 billion years of cosmological time to produce a halo on the same scale as the Milky Way's. The clumps within the halo are the remnants of mergers in which the cores of smaller halos survived as gravitationally bound subhalos orbiting within the larger host system.

The simulation produced five massive subhalos (each more than 30 million times the mass of the Sun) and many smaller ones within the inner 10 percent of the host halo. Yet only one known dwarf galaxy (Sagittarius) is that close to the center of the Milky Way, Diemand said.

"There are big clumps of dark matter in the same region where the disk of the Milky Way would be. So even in the local neighborhood of our solar system, the distribution of dark matter may be more complicated than we have assumed," he said.

Astronomers may be able to detect clumps of dark matter within the Milky Way's halo with future gamma-ray telescopes, but only if the dark matter consists of the types of particles that would give rise to gamma-ray emissions. Certain dark matter candidates--such as the neutralino, a theoretical particle predicted by supersymmetry theory--could annihilate (that is, be mutually destroyed) in collisions, generating new particles and emitting gamma rays.

"Existing gamma-ray telescopes have not detected dark matter annihilation, but upcoming experiments will be more sensitive, so there is some hope that individual subhalos may produce an observable signature," Kuhlen said.

In particular, astronomers look forward to interesting results from the Gamma Ray Large Area Space Telescope (GLAST), scheduled for launch in 2007, he said.

The simulation also provides a useful tool for observational astronomers studying the oldest stars in our galaxy by providing a link between current observations and earlier phases of galaxy formation, Diemand said.

"The first small galaxies formed very early, about 500 million years after the Big Bang, and there are still today stars in our galaxy that formed at this early time, like a fossil record of early star formation. Our simulation can provide the context for where those old stars came from and how they ended up in dwarf galaxies and in certain orbits in the stellar halo today," Diemand said.

SPACEALERTNOW.COM
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Nasa and Google reach for the stars

By Chris Nuttall in San Francisco

Published: December 19 2006 01:00 | Last updated: December 19 2006 01:00

Google is extending its reach to the stars in an agreement with Nasa that will allow it to present web visualisations of the US space agency’s data on the universe.

Nasa’s Ames Research Center in Silicon Valley on Monday announced a “Space Act Agreement” with Google that would include collaboration on large-scale data management and massively distributed computing as well as focusing on making the most useful of Nasa’s information available over the internet.

The agreement follows Google’s decision last year to build a 1m square foot campus in a science park linked to the research centre.

There are plans for real-time weather visualisation and forecasting, high-resolution 3-D maps of the moon and Mars and real-time tracking of the International Space Station and the space shuttle.

Google Earth, the software programme that maps the planet, will incorporate Nasa data into future releases.

“This agreement between Nasa and Google will soon allow every American to experience a virtual flight over the surface of the moon or through the canyons of Mars,” said Michael Griffin, Nasa administrator.

Chris Kemp, business development director at Ames, said Nasa had more information on the planet and universe than any other entity in history, but much of it was scattered and difficult to access.

“We are bringing together some of the best research scientists and engineers to form teams to make more of Nasa’s vast information accessible,” he said.

Sergey Brin and Larry Page, Google’s founders, are fascinated with space.

Mr Page is on the board of the X Prize Foundation, which uses competitions to foster breakthroughs in space.

Their Google Maps service includes charts of the moon and they have hired Vint Cerf, who has worked with Nasa on the concept of an interplanetary internet, as their Chief Internet Evangelist.

Copyright The Financial Times Limited 2006
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Tripoli Six Sentenced to Die
The Times     December 20, 2006

Gaddafi faces outrage as nurses on mercy mission are sentenced to die
Charles Bremner in Paris
# Six blamed for giving children HIV
# Second trial after seven years in jail

Five nurses who travelled to Libya to care for sick children were facing death by firing squad last night after being found guilty of deliberately infecting 426 young patients with HIV.

Their conviction, after seven years in jail and two trials, prompted an international outcry and raised the stakes for Colonel Muammar Gaddafi as he tries to regain favour with Europe and the US.

Legal appeals are expected to lead to fresh diplomatic negotiations aimed at a face-saving arrangement for the Libyan leader, who faces domestic pressure for vengeance against an alleged foreign plot to infect children with the virus.

The five Bulgarian women wept as Judge Mahmoud Haouissa pronounced the sentences at the end of a trial that was condemned by scientists, Western governments and human rights organisations.

Ashraf Alhajouj, a Palestinian doctor in his late thirties who received the same sentence, sat impassively behind the bars of the dock. “The verdict doesn’t change anything. We are still innocent,” he said.

The court also ordered the Libyan State to pay the families between $250,000 (£127,000) and $900,000 for each victim. The defendants’ lawyer said that they would appeal.

Aids experts and 114 Nobel prizewinners had called for the swift release of the medical workers. However, relatives of the infected children were delighted. Families celebrated by dancing outside the court. “We are happy,” said Subhy Abdullah, whose daughter Mona, 7, died of Aids contracted at al-Fateh Children’s Hospital in Benghazi.

The death of an eight-year-old boy this week brought to 53 the total of deaths in an epidemic that is seen in Benghazi as a plot to kill Muslims.

However, Ali al-Hasnawi, the Justice Minister, said that there could be “a complete revision of the case”, which had already been tried once before and rejected on appeal. Diplomats see the sentences as a prelude to new contacts between Colonel Gaddafi and Western governments who are keen to keep his country within their fold. Last year the European Union opened the way to a compromise over the affair with a Benghazi action plan. This sent European doctors to the Mediterranean city to provide training and advice in setting up an HIV treatment centre. Most of the surviving children are being treated in hospitals in France and Italy at Colonel Gaddafi’s expense.

The six were part of a larger group of volunteers who went to al-Fateh hospital in 1998. In that year 426 children were confirmed as being HIV-positive. The following year, 19 of the foreigners were arrested, but 13 were later released.

In May 2004 the remaining six — Christiana Valcheva, Dr Alhajouj, Snezhana Dimitrova, 54, Alia Cherveniashka, 51, Nasya Nenova, 40 and Valentina Siropoulo, 47 — were sentenced to death by firing squad for “undermining the security of the State”.

The court ignored testimony from Professor Luc Montagnier — the French doctor who was a co-discoverer of HIV — that the virus was active in the hospital before the nurses began their contracts there.

Colonel Gaddafi fomented anti-foreigner feeling, saying that the CIA or the Israeli Mossad had designed a strain of killer virus and given it to the medical staff to experiment on Libyan children. Now the colonel is seen by experts as using the Benghazi Six as a pawn in his discussions over oil, arms and aircraft, and Middle Eastern diplomacy. 

Twists and turns for the Benghazi Six

February 1999 19 Bulgarian health workers arrested on suspicion of spreading HIV

2000 Five Bulgarian nurses and two doctors — one Bulgarian, one Palestinian — go on trial

2001 Court calls for the death sentence

2002 Three of the accused retract confessions, saying they were given under duress

2003 French specialists testify that HIV was caused by poor hygiene

2004 Nurses and Palestinian doctor sentenced to death; Bulgarian doctor sentenced to four years in jail for currency smuggling. Bulgaria rejects Libyan offer to drop the case in exchange for $10 million for each infected child

2005 Ten Libyan officers accused of torturing the health workers acquitted

Source: agencies

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Researchers identify a 'heartbeat' in Earth's climate

A few years ago, an international team of researchers went to the middle of the Pacific Ocean and drilled down five kilometers below sea level in an effort to uncover secrets about the earth's climate history. They exceeded their expectations and have published their findings in the Dec. 22 edition of the journal Science.

The researchers' drilling produced pristine samples of marine microfossils, otherwise known as foraminifera. Analysis of the carbonate shells of these microfossils, which are between 23 million to 34 million years-old, has revealed that the Earth's climate and the formation and recession of glaciation events in the Earth's history have corresponded with variations in the earth's natural orbital patterns and carbon cycles.

The researchers were particularly interested in these microfossils because they came from the Oligocene epoch, a time in Earth's history known for falling temperatures.

"The continuity and length of the data series we gathered and analyzed allowed for unprecedented insights into the complex interactions between external climate forcing, the global carbon cycle and ice sheet oscillations," said Dr. Jens Herrle, co-author of the paper and a micropaleontology professor at the University of Alberta.

The authors also show how simple models of the global carbon cycle, coupled to orbital controls of global temperature and biological activity, are able to reproduce the important changes observed after the world entered an "ice-house" state about 34 million years ago.

In the early half of the 20th century, Serbian physicist Milutin Milankovitch first proposed that cyclical variations in the Earth-Sun geometry can alter the Earth's climate and these changes can be discovered in the Earth's geological archives, which is exactly what this research team, consisting of members from the United Kingdom, the U.S. and Canada, has done.

"This research is not only concerned with the climate many millions-of-years-ago. Researching and understanding 'extreme' climate events from the geological past allows us to better tune climate models to understand present and future events, and the response to major perturbations of Earth's climate and the global carbon cycle, Herrle added.

eurekalert.org

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Hubble's main camera stops working
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE"
Posted: January 29, 2007

A state-of-the-art camera aboard the Hubble Space Telescope has been knocked out of action by an electrical glitch, curtailing the flow of high-resolution imagery from the aging observatory until new instruments can be installed during a final shuttle servicing mission in 2008.

During that flight, a new camera and spectrograph will be installed, along with six new batteries and a suite of stabilizing gyroscopes that should extend Hubble's scientific life until at least 2013 and possibly longer.

But with the apparent demise of the Advanced Camera for Surveys, installed during the most recent shuttle visit in March 2002, the telescope's most spectacular visible-light images of deep space splendors will be on hold, a disappointment to astronomers around the world.

The camera was engineered to last at lest five years and "we always hope we will meet not only the design lifetime but we'll also get a bonus and that these instruments will live beyond that," Preston Burch, Hubble program manager at NASA's Goddard Space Flight Center in Greenbelt, Md., told reporters today. "So obviously we're disappointed."

Given the complexity of the five-spacewalk servicing mission planned for 2008, NASA is unlikely to add any additional repair work to the astronauts' flight plan.

"If you look at Servicing Mission 4 right now, it's very heavily subscribed," Burch said. "So something would need to come off the repair list (to address the ACS problem) and our preliminary discussions with knowledgeable scientists ... have indicated that's probably not a desirable thing to want to do.

"I wouldn't want to say it's totally impossible if we wanted to put this on a crash basis, but it would require considerable additional effort, time and money to do that. ... At first blush, this doesn't look very attractive."

But Burch said installation of the new Wide Field Camera 3 and the planned repair of a spectrographic instrument already aboard the space telescope will replace and extend the lost capability of the Advanced Camera for Surveys.

In the meantime, engineers are conducting a detailed technical review to make sure the electrical problems that hobbled ACS will not affect the Wide Field Camera 3 or the new Cosmic Origins Spectrograph scheduled for installation in 2008.

For redundancy, the ACS was built with dual power and data systems. On June 30, 2006, an electrical glitch knocked one electrical system, known as Side A, out of action.

The B channel failed Jan. 27, apparently because of an unrelated electrical issue. Pressure sensors detected a presumed puff of smoke when the electrical malfunction occurred and while engineers do not believe the telescope's optical system was contaminated, they do not know exactly what went wrong.

"It's sort of like 'CSI: Greenbelt,'" Burch said in a telephone interview. "We may never know."

Engineers may re-power the A side electronics to permit limited operations with one ACS sensor but this so-called "solar blind" channel is used primarily for low-resolution ultraviolet imaging. Barring a complex orbital repair job, high-resolution visible light pictures will no longer be possible with ACS.

Burch said the B-Side glitch is similar to an electrical problem that earlier affected the Space Telescope Imaging Spectrograph, an instrument shuttle astronauts hope to repair during the 2008 servicing mission.

The similarity in failure modes "is also giving us reason to want to bore into the circuit design and part selection and stuff like that to doubly insure we don't have some kind of latent defect waiting in the wings for COS and WFC-3."

During an earlier review, "we uncovered a lot of workmanship issues ... in the past year and those things have been addressed," Burch said. "It's entirely possible that what just occurred on ACS could very well be a workmanship kind of issue. We don't really know. ... We'll be boring into that very heavily to try to make sure the best we can that the COS and Wide Field 3 are the very best we can make them."

Engineers are hopeful no such problems will be found. With launch now less than two years away, Burch said, "if something like that surfaces, that would be a setback and put a lot of pressure on the program."

Hubble Servicing Mission No. 4 - SM-4 - will be flown aboard the shuttle Atlantis in September 2008. It is the only non-space station mission left on the shuttle manifest, a reflection of the high scientific priority attached to keeping the venerable observatory in operation.

Five back-to-back spacewalks will be required to install six new batteries, six new gyroscopes, the Wide Field Camera 3, the Cosmic Origins Spectrograph and a replacement fine guidance sensor to help the observatory find and track its targets.

The astronauts also will attempt to fix the broken Space Telescope Imaging Spectrograph, a complex task that will require the removal of 111 non-captive screws and the replacement of a power supply circuit board. It is considered the most challenging Hubble repair job since two spacewalking astronauts helped replace a power control unit in 2002.

In addition, Atlantis' crew will install a cooling system to lower the spectrometer's operating temperature, repair degraded thermal insulation and install a fixture that will permit the eventual attachment of a small rocket module to drop it safely out of orbit when it is no longer operational.

The Wide Field Camera 3, installed in place of the current Wide Field Planetary Camera 2, will provide high-resolution optical coverage from the near-infrared region of the spectrum to the ultraviolet.

The Cosmic Origins Spectrograph, sensitive to ultraviolet wavelengths, will take the place of a no-longer-used instrument known as COSTAR that once was used to correct for the spherical aberration of Hubble's primary mirror. All current Hubble instruments are equipped with their own corrective optics

If SM-4 is successful, engineers believe Hubble will remain scientifically productive at least through 2013, an additional five years beyond what could be expected based on the current health of its aging batteries and gyroscopes. With any luck at all, the telescope will still be operating when its replacement, the huge infrared-sensitive James Webb Space Telescope, is launched around 2013.

In the meantime, Hubble's two new science instruments will help the observatory address some of the most fundamental questions in astrophysics and cosmology, including the nature of the so-called dark energy believed to be accelerating the expansion of the universe, and the evolution of galaxies in the wake of the big bang.


Source: Spaceflightnow.org
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FSU anthropologist confirms 'Hobbit' indeed a separate species
Dean Falk led international team in brain analysis of ancient hominid

TALLAHASSEE, Fla. -- After the skeletal remains of an 18,000-year-old, Hobbit-sized human were discovered on the Indonesian island of Flores in 2003, some scientists thought that the specimen must have been a pygmy or a microcephalic — a human with an abnormally small skull.

Not so, said Dean Falk, a world-renowned paleoneurologist and chair of Florida State University's anthropology department, who along with an international team of experts created detailed maps of imprints left on the ancient hominid's braincase and concluded that the so-called Hobbit was actually a new species closely related to Homo sapiens.

Now after further study, Falk is absolutely convinced that her team was right and that the species cataloged as LB1, Homo floresiensis, is definitely not a human born with microcephalia — a somewhat rare pathological condition that still occurs today. Usually the result of a double-recessive gene, the condition is characterized by a small head and accompanied by some mental retardation.

"We have answered the people who contend that the Hobbit is a microcephalic," Falk said of her team's study of both normal and microcephalic human brains published in the Jan. 29 issue of the journal PNAS (Proceedings of the National Academy of Sciences of the United States).

The debate stemmed from the fact that archaeologists had found sophisticated tools and evidence of a fire near the remains of the 3-foot-tall adult female with a brain roughly one-third the size of a contemporary human.

"People refused to believe that someone with that small of a brain could make the tools. How could it be a sophisticated new species?"

But that's exactly what it is, according to Falk, whose team had previously created a "virtual endocast" from a three-dimensional computer model of the Hobbit's braincase, which reproduces the surface of the brain including its shape, grooves, vessels and sinuses. The endocasts revealed large parts of the frontal lobe and other anatomical features consistent with higher cognitive processes.

"LB1 has a highly evolved brain," she said. "It didn't get bigger, it got rewired and reorganized, and that's very interesting."

In this latest study, the researchers compared 3-D, computer-generated reconstructions of nine microcephalic modern human brains and 10 normal modern human brains. They found that certain shape features completely separate the two groups and that Hobbit classifies with normal humans rather than microcephalic humans in these features. In other ways, however, Hobbit's brain is unique, which is consistent with its attribution to a new species.

Comparison of two areas in the frontal lobe, the temporal lobe and the back of the brain show the Hobbit brain is nothing like a microcephalic's and is advanced in a way that is different from living humans. In fact, the LB1 brain was the "antithesis" of the microcephalic brain, according to Falk, a finding the researchers hope puts this part of the Hobbit controversy to rest.

It's time to move on to other important questions, Falk said, namely the origin of this species that co-existed at the same time that Homo sapiens was presumed to be the Earth's sole human inhabitant.

"It's the $64,000 question: Where did it come from?" she said. "Who did it descend from, who are its relatives, and what does it say about human evolution? That's the real excitement about this discovery."

###

Falk's co-authors on the PNAS paper, "Brain shape in human microcephalics and Homo floresiensis," are Charles Hildebolt, Kirk Smith and Fred Prior of the Washington University School of Medicine in St. Louis; M.J. Morwood of the University of New England in Australia; Thomas Sutikna, E. Wayhu Saptomo and Jatmiko of the Indonesian Centre for Archaeology in Indonesia; Herwig Imhof of the Medical University of Vienna, Austria; and Horst Seidler of the University of Vienna, Austria.


SOURCE: EUREKALERT.ORG
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Physicists find way to 'see' extra dimensions

MADISON - Peering backward in time to an instant after the big bang, physicists at the University of Wisconsin-Madison have devised an approach that may help unlock the hidden shapes of alternate dimensions of the universe.

A new study demonstrates that the shapes of extra dimensions can be "seen" by deciphering their influence on cosmic energy released by the violent birth of the universe 13 billion years ago. The method, published today (Feb. 2) in Physical Review Letters, provides evidence that physicists can use experimental data to discern the nature of these elusive dimensions - the existence of which is a critical but as yet unproven element of string theory, the leading contender for a unified "theory of everything."

Scientists developed string theory, which proposes that everything in the universe is made of tiny, vibrating strings of energy, to encompass the physical principles of all objects from immense galaxies to subatomic particles. Though currently the front-runner to explain the framework of the cosmos, the theory remains, to date, untested.

The mathematics of string theory suggests that the world we know is not complete. In addition to our four familiar dimensions - three-dimensional space and time - string theory predicts the existence of six extra spatial dimensions, "hidden" dimensions curled in tiny geometric shapes at every single point in our universe.

Don't worry if you can't picture a 10-dimensional world. Our minds are accustomed to only three spatial dimensions and lack a frame of reference for the other six, says UW-Madison physicist Gary Shiu, who led the new study. Though scientists use computers to visualize what these six-dimensional geometries could look like (see image), no one really knows for sure what shape they take.

The new Wisconsin work may provide a long-sought foundation for measuring this previously immeasurable aspect of string theory.

According to string theory mathematics, the extra dimensions could adopt any of tens of thousands of possible shapes, each shape theoretically corresponding to its own universe with its own set of physical laws.

For our universe, "Nature picked one - and we want to know what that one looks like," explains Henry Tye, a physicist at Cornell University who was not involved in the new research.

Shiu says the many-dimensional shapes are far too small to see or measure through any usual means of observation, which makes testing this crucial aspect of string theory very difficult. "You can theorize anything, but you have to be able to show it with experiments," he says. "Now the problem is, how do we test it?"

He and graduate student Bret Underwood turned to the sky for inspiration.

Their approach is based on the idea that the six tiny dimensions had their strongest influence on the universe when it itself was a tiny speck of highly compressed matter and energy - that is, in the instant just after the big bang.

"Our idea was to go back in time and see what happened back then," says Shiu. "Of course, we couldn't really go back in time."

Lacking the requisite time machine, they used the next-best thing: a map of cosmic energy released from the big bang. The energy, captured by satellites such as NASA's Wilkinson Microwave Anisotropy Probe (WMAP), has persisted virtually unchanged for the last 13 billion years, making the energy map basically "a snapshot of the baby universe," Shiu says. The WMAP experiment is the successor to NASA's Cosmic Background Explorer (COBE) project, which garnered the 2006 Nobel Prize in physics.

Just as a shadow can give an idea of the shape of an object, the pattern of cosmic energy in the sky can give an indication of the shape of the other six dimensions present, Shiu explains.

To learn how to read telltale signs of the six-dimensional geometry from the cosmic map, they worked backward. Starting with two different types of mathematically simple geometries, called warped throats, they calculated the predicted energy map that would be seen in the universe described by each shape. When they compared the two maps, they found small but significant differences between them.

Their results show that specific patterns of cosmic energy can hold clues to the geometry of the six-dimensional shape - the first type of observable data to demonstrate such promise, says Tye.

Though the current data are not precise enough to compare their findings to our universe, upcoming experiments such as the European Space Agency's Planck satellite should have the sensitivity to detect subtle variations between different geometries, Shiu says.

"Our results with simple, well-understood shapes give proof of concept that the geometry of hidden dimensions can be deciphered from the pattern of cosmic energy," he says. "This provides a rare opportunity in which string theory can be tested."

Technological improvements to capture more detailed cosmic maps should help narrow down the possibilities and may allow scientists to crack the code of the cosmic energy map - and inch closer to identifying the single geometry that fits our universe.

The implications of such a possibility are profound, says Tye. "If this shape can be measured, it would also tell us that string theory is correct."

###

The new work was funded by grants from the National Science Foundation, the U.S. Department of Energy, and the Research Corp.


SOURCE: EUREKALERT.ORG
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http://www.newscientist.com/article/dn11140-fatfighting-pill-gains-approval-in-us.html


The first over-the-counter weight-loss pill won approval from US health officials on Wednesday,

 despite health concerns from consumer groups.

The drug orlistat – made by GlaxoSmithKline (GSK) and sold as Alli – reduces the amount of fat the body absorbs from food. It is a half-dose version of a prescription medicine called Xenical, sold by Roche.

The Food and Drug Administration (FDA) approved Alli for use by overweight adults and stressed the drug should be combined with a reduced-calorie, low-fat diet and exercise. "This drug is only going to be effective if used in conjunction with a weight-loss programme," said Charles Ganley, FDA's head of non-prescription drug products.

The drug's packaging will say that for every 5 pounds lost through diet, Alli can help a person drop 2 or 3 pounds more. According to Ganley, studies by GSK found 28% of Alli users lost 5% to 10% of their body weight over six months, compared to about 18% who took a placebo.

Alli works by reducing the amount of the fat that the body absorbs by about one-quarter. The undigested fat is eliminated through bowel movements, which can cause side effects such as gas, diarrhoea and an oily discharge.

Vitamin supplements
Eating a low-fat diet can reduce the side effects, GSK and the FDA said in a statement. Alli users were also advised to take a multivitamin at bedtime to make up for the possible loss of certain nutrients, the FDA added.

Alli is now the only non-prescription weight-loss remedy with FDA approval, although many companies sell over-the-counter supplements that claim weight-loss benefits.

Consumer group Public Citizen, which has urged a ban on prescription Xenical, said Alli should not have been approved because of precancerous colon lesions linked to the drug in animal studies. The group also described the drug's benefits as "marginal."

Alli will cost about $2 a day and be in stores by summer, said GSK’s Steven Burton. Glaxo previously estimated that five to six million Americans would buy Alli over the counter. Burton said the potential market was likely to be larger, but declined to give sales projections.



NewScientist.com news service
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Narcolepsy hints at drug for insomniacs


Trouble sleeping? Insomniacs can take heart from a new drug that makes the brain enter a state similar to narcolepsy.

People with narcolepsy suddenly and unexpectedly fall asleep, probably because of defective orexin neurons in the hypothalamus. These normally release proteins called orexins that are needed to keep us awake.

Catherine Brisbare-Roch at Actelion Pharmaceuticals in Allschwil, Switzerland, and her colleagues have developed a drug that blocks orexin receptors, in turn reducing the neurons' firing rate. Preliminary studies suggest that the drug promotes sleepiness in rats, dogs and people (Nature Medicine, DOI: 10.1038/nm1544).

Unlike other sleeping pills, the drug also increases the time spent in REM sleep, when the brain is thought to organise memories, so it may not cause the forgetfulness and memory disruption linked to regular sleeping pill use



From issue 2589 of New Scientist magazine, 06 February 2007

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Excellent article..Thanks Michael
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LSU professor resolves Einstein's twin paradox

BATON ROUGE – Subhash Kak, Delaune Distinguished Professor of Electrical and Computer Engineering at LSU, recently resolved the twin paradox, known as one of the most enduring puzzles of modern-day physics.

First suggested by Albert Einstein more than 100 years ago, the paradox deals with the effects of time in the context of travel at near the speed of light. Einstein originally used the example of two clocks – one motionless, one in transit. He stated that, due to the laws of physics, clocks being transported near the speed of light would move more slowly than clocks that remained stationary. In more recent times, the paradox has been described using the analogy of twins. If one twin is placed on a space shuttle and travels near the speed of light while the remaining twin remains earthbound, the unmoved twin would have aged dramatically compared to his interstellar sibling, according to the paradox.

“If the twin aboard the spaceship went to the nearest star, which is 4.45 light years away at 86 percent of the speed of light, when he returned, he would have aged 5 years. But the earthbound twin would have aged more than 10 years!” said Kak.

The fact that time slows down on moving objects has been documented and verified over the years through repeated experimentation. But, in the previous scenario, the paradox is that the earthbound twin is the one who would be considered to be in motion – in relation to the sibling – and therefore should be the one aging more slowly. Einstein and other scientists have attempted to resolve this problem before, but none of the formulas they presented proved satisfactory.

Kak’s findings were published online in the International Journal of Theoretical Science, and will appear in the upcoming print version of the publication. “I solved the paradox by incorporating a new principle within the relativity framework that defines motion not in relation to individual objects, such as the two twins with respect to each other, but in relation to distant stars,” said Kak. Using probabilistic relationships, Kak’s solution assumes that the universe has the same general properties no matter where one might be within it.

The implications of this resolution will be widespread, generally enhancing the scientific community’s comprehension of relativity. It may eventually even have some impact on quantum communications and computers, potentially making it possible to design more efficient and reliable communication systems for space applications.

SOURCE: EUREKAALERT.ORG
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Scientists elucidate the origin of the darkest galaxies in the universe


Ghostly galaxies composed almost entirely of dark matter speckle the universe. Unlike normal galaxies, these extreme systems contain very few stars and are almost devoid of gas. Most of the luminous matter, so common in most galaxies, has been stripped away, leaving behind a dark matter shadow. These intriguing galaxies-known as dwarf spheroidals-are so faint that, although researchers believe they exist throughout the universe, only those relatively close to Earth have ever been observed. And until recently, no scientific model proposed to unravel their origin could simultaneously explain their exceptional dark matter content and their penchant for existing only in close proximity to much larger galaxies.

Now, Stelios Kazantzidis, a researcher at Stanford University's Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), in collaboration with Lucio Mayer of the Swiss Federal Institute of Technology in Zurich and the University of Zurich, Chiara Mastropietro of the University of Munich in Germany and James Wadsley of McMaster University in Canada, has developed an elegant explanation for how galaxies come to be dominated by dark matter. Kazantzidis, who completed part of the study as a fellow at the University of Chicago's Kavli Institute for Cosmological Physics, reports his findings in the Feb. 15 issue of Nature.

"These results are so exciting because they are based on a combination of physical effects that has never before been postulated," said Kazantzidis. "This is one step toward a more complete understanding of the formation of structure in the universe, which is one of the fundamental goals of astrophysics."

Using supercomputers to create novel simulations of galaxy formation, Kazantzidis and his collaborators found that a dark matter-dominated galaxy begins life as a normal system. But when it approaches a much more massive galaxy, it simultaneously encounters three environmental effects-"ram pressure," "tidal shocking" and the cosmic ultraviolet background-that transform it into a mere dark-matter shadow of its former self.

About 10 billion years ago, when the gas-rich progenitors of dark matter-dominated galaxies originally fell into the Milky Way, the universe was hot with a radiation called the cosmic ultraviolet background. As a small satellite galaxy traveled along its elliptical path around a more massive galaxy, called the host, this radiation made the gas within the smaller galaxy hotter. This state allowed ram pressure-a sort of "wind resistance" a galaxy feels as it speeds along its path-to strip away the gas within the satellite galaxy.

Simultaneously, as the satellite galaxy moved closer to the massive system, it encountered the overwhelming gravitational force of the much larger mass. This force wrenched luminous stars from the small galaxy. Over billions of years of evolution, the satellite passed by the massive galaxy several times as it traversed its orbital path. Each time its stars shook and the satellite lost some of them as a result of a mechanism called tidal shocking. These effects conspired to eventually strip away nearly all the luminous matter-gas and stars-and left behind only a dark-matter shadow of the original galaxy.

The dark matter, on the other hand, was nongaseous and therefore unaffected by the ram pressure force or the cosmic ultraviolet background, the scientists posit. It did experience tidal shocking, but this force alone was not strong enough to pull away a substantial amount of dark matter.

The numerical simulations conducted by Kazantzidis and his collaborators constitute the most extensive calculations ever performed on this topic, consuming up to two months of supercomputing time each at the University of Zurich, the Pittsburgh Supercomputing Center and elsewhere.

"Computer models of galaxy formation in the last decade or so have focused on modeling the properties of dark matter rather than those of the more familiar baryonic [luminous] matter," said co-author Mayer. "Instead, our work suggests that we cannot understand the origin of galaxies without modeling the detailed physics of baryonic matter, even in a dark matter-dominated universe."

The scientists say this new understanding of the origin of the darkest galaxies in the universe may soon lead to fundamental insights into the nature of dark matter.

"Elucidating the nature of dark matter is one of the grandest challenges of modern cosmology," said Kazantzidis. "In the next several years, numerous experiments will attempt to detect dark matter using dwarf spheroidal galaxies as targets." Kazantzidis' work will benefit these studies by offering a better explanation of the origin of ghostly galaxies.

Mystery of the missing satellites

Additionally, the work may help to explain a long-standing discrepancy between theory and observation. The leading modern cosmological model, Lambda Cold Dark Matter ((CDM), predicts that many more small galaxies surround massive galaxies like the Milky Way and Andromeda than are currently observed. This mismatch, which is often referred to as the "missing satellites problem," has been traditionally regarded as one of the toughest challenges to the (CDM paradigm. Kazantzidis' work suggests that the process by which small galaxies are stripped of their luminous matter is common, and implies that the "missing" galaxies could exist in the form of dark matter-dominated satellites.

"These galaxies could just be too dark to detect," he said. "But their possible existence will substantially alleviate the missing satellites problem with profound implications for the predictive power of the (CDM theory." Coincidentally, in the last few months, one of the most advanced observational programs ever undertaken, the Sloan Digital Sky Survey, has revealed in the vicinity of the Milky Way a number of what appear to be ultra-faint satellite galaxies. If this finding is confirmed by follow-up observations and analysis, these newly discovered systems would be explained by Kazantzidis' calculations and would contribute to solving the long-standing missing satellites problem, he says.

SOURCE: EUREKAALERT.ORG
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Chimpanzees 'hunt using spears' 

Chimpanzees in Senegal have been observed making and using wooden spears to hunt other primates, according to a study in the journal Current Biology.
Researchers documented 22 cases of chimps fashioning tools to jab at smaller primates sheltering in cavities of hollow branches or tree trunks.

The report's authors, Jill Pruetz and Paco Bertolani, said the finding could have implications for human evolution. Chimps had not been previously observed hunting other animals with tools.

Pruetz and Bertolani made the discovery at their research site in Fongoli, Senegal, between March 2005 and July 2006.

 

http://news.bbc.co.uk/2/hi/science/nature/6387611.stm

I hope no-one tells Charlton Heston, he may shoot "the filthy apes".   [;D]
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Study reveals leaks in Antarctic 'plumbing system'
NASA NEWS RELEASE
Posted: February 24, 2007

WASHINGTON - Scientists using NASA satellites have discovered an extensive network of waterways beneath a fast-moving Antarctic ice stream that provide clues as to how "leaks" in the system impact sea level and the world's largest ice sheet. Antarctica holds about 90 percent of the world's ice and 70 percent of the world's reservoir of fresh water.

With data from NASA satellites, a team of scientists led by research geophysicist Helen Fricker of the Scripps Institution of Oceanography, La Jolla, Calif., detected for the first time the subtle rise and fall of the surface of fast-moving ice streams as the lakes and channels nearly a half-mile of solid ice below filled and emptied. Results were presented at the annual meeting of the American Association for the Advancement of Science (AAAS) in San Francisco. The study was published in the Feb. 16 issue of Science magazine.

"This exciting discovery of large lakes exchanging water under the ice sheet surface has radically altered our view of what is happening at the base of the ice sheet and how ice moves in that environment," said co-author Robert Bindschadler, chief scientist of the Laboratory for Hydrospheric and Biospheric Sciences at NASA's Goddard Space Flight Center, Greenbelt, Md.

"NASA's state-of-the-art satellite instruments are so sensitive we are able to capture an unprecedented three-dimensional look at the system beneath the thick ice sheet and measure from space changes of a mere 3 feet in its surface elevation. That is like seeing an elevation change in the thickness of a paperback book from an airplane flying at 35,000 feet."

The surface of the ice sheet appears stable to the naked eye, but because the base of an ice stream is warmer, water melts from the basal ice to flow, filling the system's "pipes" and lubricating flow of the overlying ice. This web of waterways acts as a vehicle for water to move and change its influence on the ice movement.

Moving back and forth through the system's "pipes" from one lake to another, the water stimulates the speed of the ice stream's flow a few feet per day, contributing to conditions that cause the ice sheet to either grow or decay. Movement in this system can influence sea level and ice melt worldwide.

"There's an urgency to learning more about ice sheets when you note that sea level rises and falls in direct response to changes in that ice," Fricker said. "With this in mind, NASA's ICESat, Aqua and other satellites are providing a vital public service."

In recent years, scientists have discovered more than 145 subglacial lakes, a smaller number of which composes this "plumbing system" in the Antarctic. Bindschadler and Fricker; Ted Scambos of the National Snow and Ice Data Center in Boulder, Colo.; and Laurence Padman of Earth and Space Research in Corvallis, Ore.; observed water discharging from these under-ice lakes into the ocean in coastal areas. Their research has delivered new insight into how much and how frequently these waterways "leak" water and how many connect to the ocean.

The study included observations of a subglacial lake the size of Lake Ontario buried under an active area of west Antarctica that feeds into the Ross Ice Shelf. The research team combined images from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Aqua satellite and data from the Geoscience Laser Altimeter System (GLAS) on NASA's Ice Cloud and Land Elevation Satellite (ICESat) to unveil a multi-dimensional view of changes in the elevation of the icy surface above the lake and surrounding areas during a three-year period. Those changes suggest the lake drained and that its water relocated elsewhere.

MODIS continuously takes measurements of broad-sweeping surface areas at three levels of detail, revealing the outline of under-ice lakes. ICESat's GLAS instrument uses laser altimetry technology to measure even the smallest of elevation changes in the landscape of an ice sheet. Together, data from both have been used to create a multi-year series of calibrated surface reflectance images, resulting in a new technique called satellite image differencing that emphasizes where surface slopes have changed.

Souce: spaceflightnow.com
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Detection of a colliding-wind beyond the Milky Way

EUROPEAN SPACE AGENCY NEWS RELEASE
Posted: February 25, 2007

Imagine two stars with winds so powerful that they eject an Earth's worth of material roughly once every month. Next, imagine those two winds colliding head-on. Such titanic collisions produce multimillion-degree gas, which radiates brilliantly in X-rays. Astronomers have conclusively identified the X-rays from about two-dozen of these systems in our Milky Way. But they have never seen one outside our galaxy - until now.

Thanks to the European Space Agency's XMM-Newton X-ray observatory, with help from NASA's Chandra X-ray Observatory, an international team led by Dr Yael Naze of the Universite de Liege in Belgium has found such a system in a nearby galaxy. This galaxy, the Small Magellanic Cloud, orbits the Milky Way and is located about 170 000 light-years from Earth.   

The binary system, known as HD 5980, contains two extremely massive stars, 'weighing' about 50 and 30 times the mass of the Sun. Each star radiates more than a million times as much light as the Sun, meaning they put out more light in one minute than our host star generates in an entire year.

The sheer photon pressure of this incredible outpouring of light blows off gas from each star in a supersonic 'wind'. These winds are so powerful that they carry away roughly an Earth mass each month, a rate 10 thousand million times greater than the solar wind, and at a speed 5 times faster than the solar wind itself.

HD 5980's two stars are separated by only about 90 million kilometres, roughly half Earth's average distance from the Sun. "These stars are so close to each other that if they were in our solar system they could fit inside the orbit of Venus," says Naze. As a result, the winds smash into each other with tremendous force, heating the gas and generating enormous numbers of X-rays.

"The system emits about 10 times more energy in X-rays alone than the Sun radiates over the entire spectrum," says team member Dr Michael F. Corcoran, a scientist with the Universities Space Research Association at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Using data from Chandra, the same team first reported HD 5980's highly energetic X-ray emission in 2002. But its origin was uncertain. Data taken from 2000 to 2005 with XMM-Newton shows that it is indeed produced by a wind collision.

The stars orbit each other every 20 days in a plane that is edge-on to Earth's line of sight, so the stars periodically eclipse each other. The wind collision is thus seen from different angles and through different amounts of material. XMM-Newton saw the X-ray emission rise and fall in a repeatable, predictable pattern.

"Similar X-ray variability from massive binaries inside the Milky Way have been detected, but this is the first indisputable evidence for the phenomenon outside our galaxy," says Naze. "This discovery highlights the great capabilities of modern X-ray observatories."

XMM-Newton has the largest mirrors of any X-ray observatory ever flown, and the sheer size of these mirrors allowed astronomers to monitor this distant system. HD 5980 itself is surrounded by hot interstellar material that creates a diffuse X-ray glow that makes the object difficult to study. "The Chandra data allowed us to pinpoint HD 5980 and resolve the system from the diffuse emission," says Corcoran.

HD 5980 is one of the Small Magellanic Cloud's brightest stars. Situated on the periphery of the star cluster NGC 346, the two stars are nearing the end of their lives and will eventually explode as supernovae. The more massive star, HD 5980A, is passing through a Luminous Blue Variable (LBV) phase - a short-lived, erratic stage that only the most massive stars go through. The most well-known LBV in our galaxy, Eta Carinae, produced a giant outburst that was recorded by astronomers in the 1840s. HD 5980A experienced a smaller-scale outburst that was seen in 1993-94. Its companion, HD 5980B, is an evolved Wolf-Rayet star that has already ejected much of its original envelope.

"It's interesting to be able to study an extragalactic colliding-wind binary like HD 5980 as if it were in our own galaxy", says Corcoran. "Colliding winds provide an important handle on how massive stars shed material. Being able to study them in external galaxies means we can study the effects of different compositions and environments on how these massive stars evolve. From the XMM-Newton data, we can study the delicate balance between the two winds, and determine the changing strength of the winds."

spaceflightnow.com
 
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New coating is virtual black hole for reflections

Nonreflecting material may help solar cells catch more of the sun's rays.

Researchers have created an anti-reflective coating that allows light to travel through it, but lets almost none bounce off its surface. At least 10 times more effective than the coating on sunglasses or computer monitors, the material, which is made of silica nanorods, may be used to channel light into solar cells or allow more photons to surge through the surface of a light-emitting diode (LED).

Publishing in the March 1, 2007, Nature Photonics, lead author Jong Kyu Kim and a team from Rensselaer Polytechnic Institute in Troy, N.Y., reveal how they crafted the coating, which reflects almost as little light as do molecules of air.

Guided by National Science Foundation-supported electrical engineer Fred Schubert, the researchers developed a process based on an already common method for depositing layers of silica, the building block of quartz, onto computer chips and other surfaces.

The method grows ranks of nanoscale rods that lie at the same angle. That degree of the angle is determined by temperature. Under a microscope, the films look like tiny slices of shag carpet.

By laying down multiple layers, each at a different angle, the researchers created thin films that are uniquely capable of controlling light. With the right layers in the right configuration, the researchers believe they can even create a film that will reflect no light at all.

One critical application for the material is in the development of next-generation solar cells. By preventing reflections, the coating would allow more light, and more wavelengths of light, to transmit through the protective finish on a solar cell surface and into the cell itself. Engineers may be able to use such a technique to boost the amount of energy a cell can collect, bypassing current efficiency limits.

Another application would involve coating LEDs to eliminate reflections that cut down the amount of light the LED can emit. The researchers hope the efficiency gains could allow the light sources to compete more effectively with fluorescent and incandescent bulbs. So, they will next focus their attention on solid state lighting.


Source: eurekalert.org
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Green light for Australian ban on old-style bulb


Agencies in Canberra and Sydney
Wednesday February 21, 2007
The Guardian

 
Photograph: Guardian
 
Australia is to ban incandescent lightbulbs in an effort to curb greenhouse gas emissions, with the government saying yesterday they would be phased out within three years.
The environment minister, Malcolm Turnbull, said yellow incandescent bulbs, which have been virtually unchanged for 125 years, would be replaced by more efficient compact fluorescent bulbs by 2009. "By that stage you simply won't be able to buy incandescent lightbulbs, because they won't meet the energy standard," he said in a radio interview.


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Paleontologists discover new mammal from Mesozoic Era

Animals shows intermediate ear structure in evolution of modern mammals

An international team of American and Chinese paleontologists has discovered a new species of mammal that lived 125 million years ago during the Mesozoic Era, in what is now the Hebei Province in China.

The new mammal, documented in the March 15 issue of the journal Nature, provides first-hand evidence of early evolution of the mammalian middle ear--one of the most important features for all modern mammals. The discovery was funded by the National Science Foundation (NSF).

"This early mammalian ear from China is a rosetta-stone type of discovery which reinforces the idea that development of complex body parts can be explained by evolution, using exquisitely preserved fossils," said H. Richard Lane, program director in NSF's Division of Earth Sciences, which co-funded the discovery with NSF's Division of Environmental Biology and its Assembling the Tree of Life (AToL) program.

Named Yanoconodon allini after the Yan Mountains in Hebei, the fossil was unearthed in the fossil-rich beds of the Yixian Formation and is the first Mesozoic mammal recovered from Hebei. The fossil site is about 300 kilometers outside of Beijing.

The researchers discovered that the skull of Yanoconodon revealed a middle ear structure that is an intermediate step between those of modern mammals and those of near relatives of mammals, also known as mammaliaforms.

"This new fossil offers a rare insight in the evolutionary origin of the mammalian ear structure," said Zhe-Xi Luo, a paleontologist at the Carnegie Museum of Natural History (CMNH) in Pittsburgh, Pa. "Evolution of the ear is important for understanding the origins of key mammalian adaptations."

Mammals have highly sensitive hearing, far better than the hearing capacity of all other vertebrates, scientists have found. Consequently, paleontologists and evolutionary biologists have been searching for more than a century for clues to the evolutionary origins of mammal ear structure.

Mammalian hearing adaptation is made possible by a sophisticated middle ear of three tiny bones, known as the hammer (malleus), the anvil (incus) and the stirrup (stapes), plus a bony ring for the eardrum (tympanic membrane).

The mammal middle ear bones evolved from the bones of the jaw hinge in their reptilian relatives. However, paleontologists long have attempted to understand the evolutionary pathway via which these precursor jaw bones became separated from the jaw and moved into the middle ear of modern mammals.

"Now we have a definitive piece of evidence, in a beautifully preserved fossil split on two rock slabs," said Luo. "Yanoconodon clearly shows an intermediate condition in the evolutionary process of how modern mammals acquired their middle ear structure."

Yanoconodon is about 5 inches (or 15 cm) long and estimated to weigh about 30 grams. Its teeth are notable for the three cusps in a straight line on molars (thus known as a triconodont) for feeding on insects and worms. It has a long body, short and sprawling limbs and claws that were ideal for either digging or living on the ground.

In addition to its unique ear structure, Yanoconodon also has a surprisingly high number of 26 thoracic ("chest") and lumbar ("waist") vertebrae, unlike most living and extinct terrestrial mammals that commonly have 19 or 20 thoracic and lumbar vertebrae. The extra vertebrae give Yanoconodon a more elongated body form, in contrast to its relatively shorter and very primitive limb and foot structures. The new mammal also has lumbar ribs, a rare feature among modern mammals.

"The discoveries of exquisitely preserved Mesozoic mammals from China have built the evidence such that biologists and paleontologists are able to make sense of how developmental mechanisms have impacted the morphological evolution of the earliest mammals," said Luo.


SOURCE: EUREKALERT
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Keeping the body in sync -- the stability of cellular clocks

A study in Switzerland uses the tools of physics to show how our circadian clocks manage to keep accurate time in the noisy cellular environment.

In an article appearing March 13 in the journal Molecular Systems Biology, researchers from the Ecole Polytechnique Federale de Lausanne demonstrate that the stability of cellular oscillators depends on specific biochemical processes, reflecting recent association studies in families affected by advanced sleep phase syndrome.

Circadian rhythms are cyclical changes in physiology, gene expression, and behavior that run on a cycle of approximately one day, even in conditions of constant light or darkness. Peripheral organs in the body have their own cellular clocks that are reset on a daily basis by a central master clock in the brain. The operation of the cellular clocks is controlled by the coordinated action of a limited number of core clock genes. The oscillators work like this: the cell receives a signal from the master pacemaker in the hypothalamus, and then these clock genes respond by setting up concentration gradients that change in a periodic manner. The cell “interprets” these gradients and unleashes tissue-specific circadian responses. Some examples of output from these clocks are the daily rhythmic changes in body temperature, blood pressure, heart rate, concentrations of melatonin and glucocorticoids, urine production, acid secretion in the gastrointestinal tract, and changes in liver metabolism.

In the tiny volume of the cell, however, the chemical environment is constantly fluctuating. How is it possible for all these cell-autonomous clocks to sustain accurate 24-hour rhythms in such a noisy environment?

Using mouse fibroblast circadian bioluminescence recordings from the Schibler Lab at the University of Geneva, the researchers turned to dynamical systems theory and developed a mathematical model that identified the molecular parameters responsible for the stability of the cellular clocks. Stability is a measure of how fast the system reverts to its initial state after being perturbed.

“To my knowledge we are the first to discuss how the stability of the oscillator directly affects bioluminescence recordings,” explains Felix Naef, a systems biology professor at EPFL and the Swiss Institute for Experimental Cancer Research. “We found that the phosphorylation and transcription rates of a specific gene are key determinants of the stability of our internal body clocks.”

This result is consistent with recent research from the University of California, San Francisco involving families whose circadian clocks don’t tick quite right. These families’ clocks are shorter than 24 hours, and they also have mutations in oscillator-related genes. The current results shed light on how a genetically-linked phosphorylation event gone wrong could lead to inaccurate timing of our body clockworks.

SOURCE: EUREKALERT
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Robotic telescope unravels mystery of cosmic blasts

Scientists have used the world's largest robotic telescope to make the earliest-ever measurement of the optical polarisation* of a Gamma Ray Burst (GRB) just 203 seconds after the start of the cosmic explosion. This finding, which provides new insight into GRB physics, is published in Science today (15th March 2007).

The scientists from Liverpool John Moores University and colleagues in the UK, Italy, France and Slovenia used the Liverpool Telescope on the island of La Palma and its novel new polarimeter, RINGO, to perform the measurement following detection of the burst by NASA's Swift satellite.

Gamma Ray Bursts are the most instantaneously powerful explosions in the Universe and are identified as brief, intense and completely unpredictable flashes of high energy gamma rays on the sky. They are thought to be produced by the death throes of a massive star and signal the birth of a new black hole or neutron star (magnetar) and ejection of an ultra-high speed jet of plasma. Until now, the composition of the ejected material has remained a mystery and, in particular the importance of magnetic fields has been hotly debated by GRB scientists.

The Liverpool measurement was obtained nearly 100 times faster than any previously published optical polarisation measurement for a GRB afterglow and answers some fundamental questions about the presence of magnetic fields.

Principal author of the Science paper and GRB team leader Dr Carole Mundell of the Astrophysics Research Institute, Liverpool John Moores University, said "Our new measurements, made shortly after the Gamma Ray Burst, show that the level of polarisation in the afterglow is very low. Combined with our knowledge of how the light from this explosion faded, this rules-out the presence of strong magnetic fields in the emitting material flowing out from the explosion - a key element of some theories of GRBs."

The so-called optical afterglow is thought to originate from light emitted when this ejected material impacts the gas surrounding the star. In the first few minutes after the initial burst of gamma rays, the optical light carries important clues to the origin of these catastrophic explosions; capturing this light at the earliest possible opportunity and measuring its properties is ideally suited to the capabilities of large robotic telescopes like the Liverpool Telescope.

Lord Martin Rees, Astronomer Royal and President of the Royal Society said "We are still flummoxed about the underlying 'trigger' for gamma ray bursts, and why they sometimes emit bright flashes of light. Theorists have a lot of tentative ideas, and these observations narrow down the range of options."

Professor Keith Mason, CEO of the Particle Physics and Astronomy Council (PPARC) and UK lead investigator on Swift’s Ultra Violet/Optical Telescope, said, "This result demonstrates well the effectiveness of Swift’s rapid response alert system, allowing robotic telescopes, such as the Liverpool Telescope, to follow up gamma ray bursts within seconds, furthering our knowledge with each detection."

SOURCE: EUREKALERT
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A dead star seen snacking on shredded asteroid
SPITZER SCIENCE CENTER NEWS RELEASE


For the last two years, astronomers have suspected that a nearby white dwarf star called GD 362 was "snacking" on a shredded asteroid. Now, an analysis of chemical "crumbs" in the star's atmosphere conducted by NASA's Spitzer Space Telescope has confirmed this suspicion.

"This is a really fascinating system, that could offer clues to what our solar system may look like in approximately five billion years when our Sun becomes a white dwarf," said Dr. Michael Jura, of the University of California at Los Angeles (UCLA).

White dwarfs are essentially the glowing embers of stars that were once like our Sun. Sun-like stars spend most of their lives producing energy by fusing hydrogen atoms into "heavier" helium atoms. Our Sun is currently doing this.

Once the Sun-like star runs out of hydrogen, helium atoms will fuse to produce other heavier elements like carbon, which will eventually sink to the star's core. Meanwhile, the heat released during this helium fusion is so strong that the will star expand and vaporize all dust, rocks and planets that orbit nearby. At this stage, the star is called a "red giant." Ultimately, the red giant will shed its external layers, exposing a dense, hot core about the size of Earth, known as a "white dwarf."

Closely orbiting planets, asteroids, and dust are not expected to survive the red-giant phase of a Sun-like star's life, so astronomers were shocked to find so much dust around the white dwarf GD 362. According to Jura, GD 362 has been a white dwarf for approximately 900 million years -- so surrounding dust should have already been destroyed. He also notes that astronomers were surprised to find chemical elements heavier than hydrogen and helium in GD 362's atmosphere, because these elements should have already sunk to the star's core. When an abundance of heavy elements were first found in GD 362's atmosphere in 2004, scientists were not sure where they came from.

An explanation came in 2005, when two teams of astronomers independently found evidence for dust orbiting GD 362. Both groups argued that the elements in the atmosphere came from orbiting dust particles that rained onto star, and was vaporized by the white dwarf's intense heat. However, astronomers did not know where the dust came from.

Some astronomers predicted that the dust circled the star similar to the way rings of debris orbit Saturn. They believed that the ring of dust around GD 362 came from a large asteroid that had wandered too close to the star, and was shredded by the white dwarf's gravity. Meanwhile, others suspected that dust grains floated into the system from outer space and got pulled into GD 362's atmosphere.

According to Jura, new observations from Spitzer provide direct evidence for the first scenario. He notes that the silicates (sand-like dust grains) in asteroids are very different from the silicates randomly floating around the universe. Using Spitzer's infrared spectrograph instrument, Jura's team determined that the silicates in GD 362's atmosphere resembled the sand-like grains found in asteroids.

With Spitzer's Multiband Imaging Photometer (MIPS) instrument, Jura's team also noticed that the dust disk surrounding GD 362 was confined, meaning they saw an end to the dust disk.

"If this dust was floating in from the interstellar medium [or outer space] and falling onto the star, then we would see a trail of dust leading beyond this star system -- the dust disk shouldn't end. In the Spitzer observations, we see that the dust is confined to a region close to the star," said Jura.

Jura's paper on this topic was has been accepted by the Astronomical Journal. Other authors of this work include Dr. Jay Farihi, of the Gemini Observatory, Hawaii; and Drs. Ben Zuckerman and Eric Becklin, also of UCLA. Becklin led the Gemini North observations that first discovered dust in GD 362's atmosphere.

Source: spaceflightnow.com
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Star burps, then explodes
UNIVERSITY OF CALIFORNIA-BERKELEY NEWS RELEASE

BERKELEY - Tens of millions of years ago, in a galaxy far, far away, a massive star suffered a nasty double whammy.

Signs of the first shock reached Earth on Oct. 20, 2004, when the star was observed letting loose an outburst so enormous and bright that Japanese amateur astronomer Koichi Itagaki initially mistook it for a supernova. The star survived for nearly two years, however, until on Oct. 11, 2006, professional and amateur astronomers witnessed it blowing itself to smithereens as Supernova (SN) 2006jc.

"We have never observed a stellar outburst and then later seen the star explode," said University of California, Berkeley, astronomer Ryan Foley. His group studied the 2006 event with ground-based telescopes, including the 10-meter (32.8-foot) W. M. Keck telescopes in Hawaii. Narrow helium spectral lines showed that the supernova's blast wave ran into a slow-moving shell of material, presumably the progenitor's outer layers that were ejected just two years earlier. If the spectral lines had been caused by the supernova's fast-moving blast wave, the lines would have been much broader.

Another group, led by Stefan Immler of NASA's Goddard Space Flight Center in Greenbelt, Md., monitored SN 2006jc with NASA's Swift satellite and the Chandra X-ray Observatory. By observing how the supernova brightened in X-rays, a result of the blast wave slamming into the outburst ejecta, they could measure the amount of gas blown off in the 2004 outburst: about 0.01 solar mass, the equivalent of about 10 Jupiters.

"The beautiful aspect of our SN 2006jc observations is that although they were obtained in different parts of the electromagnetic spectrum, in the optical and in X-rays, they lead to the same conclusions," said Immler.

"This event was a complete surprise," added Alex Filippenko, leader of the UC Berkeley/Keck supernova group and a member of NASA's Swift satellite team. "It opens up a fascinating new window on how some kinds of stars die."

All the observations suggest that the supernova's blast wave took only a few weeks to reach the shell of material ejected two years earlier, which did not have time to drift very far from the star. As the wave smashed into the ejecta, it heated the gas to millions of degrees, hot enough to emit copious X-rays. The Swift satellite saw the supernova continue to brighten in X-rays for 100 days, something that has never been seen before in a supernova. All supernovae previously observed in X-rays have started off bright and then quickly faded to invisibility.

"You don't need a lot of mass in the ejecta to produce a lot of X-rays," noted Immler. Swift's ability to monitor the supernova's X-ray rise and decline over six months was crucial to the mass determination by Immler's team. But he added that Chandra's sharp resolution enabled his group to resolve the supernova from a bright X-ray source that appears in the field of view of Swift's X-ray telescope.

"We could not have made this measurement without Chandra," said Immler, who will submit his team's paper next week to the Astrophysical Journal. "The synergy between Swift's fast response and its ability to observe a supernova every day for a long period, and Chandra's high spatial resolution, is leading to a lot of interesting results."

Foley and his colleagues, whose paper appears in the March 10 Astrophysical Journal Letters, propose that the star recently transitioned from a Luminous Blue Variable (LBV) star to a Wolf-Rayet star. An LBV is a massive star in a brief but unstable phase of stellar evolution. Similar to the 2004 eruption, LBVs are prone to blow off large amounts of mass in outbursts so extreme that they are frequently mistaken for supernovae, events dubbed "supernova impostors." Wolf-Rayet stars are hot, highly evolved stars that have shed their outer envelopes.

Most astronomers did not expect that a massive star would explode so soon after a major outburst, or that a Wolf-Rayet star would produce such a luminous eruption, so SN 2006jc represents a puzzle for theorists.

"It challenges some aspects of our current model of stellar evolution," said Foley. "We really don't know what caused this star to have such a large eruption so soon before it went supernova."

"SN 2006jc provides us with an important clue that LBV-style eruptions may be related to the deaths of massive stars, perhaps more closely than we used to think," added coauthor and UC Berkeley astronomer Nathan Smith. "The fact that we have no well-established theory for what actually causes these outbursts is the elephant in the living room that nobody is talking about."

SN 2006jc occurred in galaxy UGC 4904, located 77 million light years from Earth in the constellation Lynx. The supernova explosion, a peculiar variant of a Type Ib, was first sighted by Itagaki, American amateur astronomer Tim Puckett and Italian amateur astronomer Roberto Gorelli.

SOURCE:SPACEFLIGHTNOW.COM
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Ancient T. rex and mastodon protein fragments discovered, sequenced
68-million-year-old T. rex proteins are oldest ever sequenced

Scientists have confirmed the existence of protein in soft tissue recovered from the fossil bones of a 68 million-year-old Tyrannosaurus rex (T. rex) and a half-million-year-old mastodon.

Their results may change the way people think about fossil preservation and present a new method for studying diseases in which identification of proteins is important, such as cancer.

When an animal dies, protein immediately begins to degrade and, in the case of fossils, is slowly replaced by mineral. This substitution process was thought to be complete by 1 million years. Researchers at North Carolina State University (NCSU) and Harvard Medical School now know otherwise.

The researchers' findings appear as companion papers in this week's issue of the journal Science.

"Not only was protein detectably present in these fossils, the preserved material was in good enough condition that it could be identified," said Paul Filmer, program director in the National Science Foundation (NSF) Division of Earth Sciences, which funded the research. "We now know much more about what conditions proteins can survive in. It turns out that some proteins can survive for very long time periods, far longer than anyone predicted."

Mary Schweitzer of NCSU and the North Carolina Museum of Natural Sciences discovered soft tissue in the leg bone of a T. rex and other fossils recovered from the Hell Creek sediment formation in Montana.

After her chemical and molecular analyses of the tissue indicated that original protein fragments might be preserved, she turned to colleagues John Asara and Lewis Cantley of Harvard Medical School, to see if they could confirm her suspicions by finding the amino acid used to make collagen, a fibrous protein found in bone.

Bone is a composite material, consisting of both protein and mineral. In modern bones, when minerals are removed, a collagen matrix--fibrous, resilient material that gives the bones structure and flexibility--is left behind. When Schweitzer demineralized the T. rex bone, she was surprised to find such a matrix, because current theories of fossilization held that no original organic material could survive that long.

"This information will help us learn more about evolutionary relationships, about how preservation happens, and about how molecules degrade over time, which could have important applications in medicine," Schweitzer said.

To see if the material had characteristics indicating the presence of collagen, which is plentiful, durable and has been recovered from other fossil materials, the scientists examined the resulting soft tissue with electron microscopy and atomic force microscopy. They then tested it against various antibodies that are known to react with collagen. Identifying collagen would indicate that it is original to T. rex--that the tissue contains remnants of the molecules produced by the dinosaur.

"This is the breakthrough that says it's possible to get sequences beyond 1 million years," said Cantley. "At 68 million years, it's still possible."

Asara and Cantley successfully sequenced portions of the dinosaur and mastodon proteins, identifying the amino acids and confirming that the material was collagen. When they compared the collagen sequences to a database that contains existing sequences from modern species, they found that the T. rex sequence had similarities to those of chickens, and that the mastodon was more closely related to mammals, including the African elephant.

The protein fragments in the T. rex fossil appear to most closely match amino acid sequences found in collagen of present-day chickens, lending support to the idea that birds and dinosaurs are evolutionarily related.

"Most people believe that birds evolved from dinosaurs, but that's based on the 'architecture' of the bones," Asara said. "This finding allows us the ability to say that they really are related because their sequences are related."

"Scientists had long assumed that the material in fossil bones would not be preserved after millions of years of burial," said Enriqueta Barrera, program director in NSF's Division of Earth Sciences. "This discovery has implications for the study of similarly well-preserved fossil material."

SOURCE: Eurekalert.org
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3.2 Billion-Year-Old Surprise: Earth Had Strong Magnetic Field

Geophysicists at the University of Rochester announce in today's issue of Nature that the Earth's magnetic field was nearly as strong 3.2 billion years ago as it is today.

The findings, which are contrary to previous studies, suggest that even in its earliest stages the Earth was already well protected from the solar wind, which can strip away a planet's atmosphere and bathe its surface in lethal radiation.

"The intensity of the ancient magnetic field was very similar to today's intensity," says John Tarduno, professor of geophysics in the Department of Earth and Environmental Sciences at the University of Rochester. "These values suggest the field was surprisingly strong and robust. It's interesting because it could mean the Earth already had a solid iron inner core 3.2 billion years ago, which is at the very limit of what theoretical models of the Earth's formation could predict."

Geophysicists point to Mars as an example of a planet that likely lost its magnetosphere early in its history, letting the bombardment of radiation from the sun slowly erode its early atmosphere. Theories of Earth's field say it's generated by the convection of our liquid iron core, but scientists have always been curious to know when Earth's solid inner core formed because this process provides an important energy source to power the magnetic field. Scientists are also interested in when Earth's protective magnetic cocoon formed.

But uncovering the intensity of a field 3.2 billion years in the past has proven daunting, and until Tarduno's research, the only data scientists could tease from the rocks suggested the field was perhaps only a tenth as strong as today's.

Tarduno had previously shown that as far back as 2.5 billion years ago, the field was just as intense as it is today, but pushing back another 700 million years in time meant he had to find a way to overcome some special challenges.

The traditional approach to measuring the ancient Earth's magnetic field would not be good enough. The technique was developed more than four decades ago, and has changed little. With the old method, an igneous rock about an inch across is heated and cooled in a chamber that is shielded from magnetic interference. The magnetism is essentially drained from the particles in the rock and then it's refilled while scientists measure how much the particles can hold.

Tarduno, however, isolates choice, individual crystals from a rock, heats them with a laser, and measures their magnetic intensity with a super-sensitive detector called a SQUID—a Superconducting Quantum Interface Device normally used in computing chip design because it's extremely sensitive to the tiniest magnetic fields.

Certain rocks contain tiny crystals like feldspar and quartz—nano-meter sized magnetic inclusions that lock in a record of the Earth's magnetic field as they cool from molten magma to hard rock. Simply finding rocks of this age is difficult enough, but these rocks have also witnessed billions of years of geological activity that could have reheated them and possibly changed their initial magnetic record.

To reduce the chance of this contamination, Tarduno picked out the best preserved grains of feldspar and quartz out of 3.2 billion-year-old granite outcroppings in South Africa. Feldspar and quartz are good preservers of the paleomagnetic record because their minute magnetic inclusions essentially take a snapshot of the field as they cool from a molten state. Tarduno wanted to measure the smallest magnetic inclusions because larger magnetic crystals can lose their original magnetic signature at much lower temperatures, meaning they are more likely to suffer magnetic contamination from later warming geological events.

Once he isolated the ideal crystals, Tarduno employed a carbon dioxide laser to heat individual crystals much more quickly than older methods, further lessening the chance of contamination. With the University's ultra-sensitive SQUID he could measure how much magnetism these individual particles contained.

"The data suggest that the ancient magnetic field strength was at least 50 percent of the present-day field, which typically measures 40 to 60 microteslas," says Tarduno. "This means that a magnetosphere was definitely present, sheltering the Earth 3.2 billion years ago."

To further ensure his readings were accurate, Tarduno also checked the alignment of the magnetism in the particles, which record the polarity of the Earth's field at that time and location. By comparing the polarity to that of other samples of similar age and location, Tarduno could ensure that his measurements were not likely from later geological heating, but truly from 3.2 billion years ago.

Tarduno is now pushing back in time to 3.5 billion-year-old rocks to further investigate when the Earth's inner core first formed, giving new insights into early Earth processes that also may have had an effect on the atmosphere and the development of life on the planet.

Rory Cottrell, research scientist in Tarduno's laboratory, is co-author on the study. This research was funded by the National Science Foundation.

Source: University of Rochester News
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XMM-Newton pinpoints intergalactic polluters
EUROPEAN SPACE AGENCY NEWS RELEASE
Posted: April 24, 2007

Warm gas escaping from the clutches of enormous black holes could be the key to a form of intergalactic 'pollution' that made life possible, according to new results from ESA's XMM-Newton space observatory.

Black holes are not quite the all-consuming monsters depicted in popular culture.

Until gas crosses the boundary of the black hole known as the Event Horizon, it can escape if heated sufficiently. For decades now, astronomers have watched warm gas from the mightiest black holes flowing away at speeds of 1000-2000 km/s and wondered just how much gas escapes this way. XMM-Newton has now made the most accurate measurements yet of the process.

The international team of astronomers, led by Yair Krongold, Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, targeted a black hole two million times more massive than the Sun at the centre of the active galaxy NGC 4051.

Previous observations had only revealed the average properties of the escaping gas. XMM-Newton has the special ability to watch a single celestial object with several instruments at the same time. With this, the team collected more detailed information about variations in the gas' brightness and ionization state.

The team also saw that the gas was escaping from much closer to the black hole than previously thought. They could determine the fraction of gas that was escaping. "We calculate that between 2-5 percent of the accreting material is flowing back out," says team member Fabrizio Nicastro, Harvard-Smithsonian Centre for Astrophysics. This was less than some astronomers had expected.

The same heating process that allows the gas to escape also rips electrons from their atomic nuclei, leaving them ionised. The extent to which this has happened in an atom is known as its ionisation state. In particular, metals always have positive ionisation states.

The warm gas contains chemical elements heavier than Hydrogen and Helium. Astronomers term them 'metals' since they are elements in which electrons are ripped away and they have positive ionisation states - like metals. They include carbon, the essential element for life on Earth. These metals can only be made inside stars, yet they pollute vast tracts of space between galaxies. Astronomers have long wondered how they arrived in intergalactic space.

This new study provides a clue. More powerful active galaxies than NGC 4051, known as quasars, populate space. They are galaxies in which the central black hole is feeding voraciously. This would mean that quasars must have escaping gas that could carry metals all the way into intergalactic space.

If quasars are responsible for spraying metals into intergalactic space, the pollution would more likely be found in bubbles surrounding each quasar. So, different parts of the Universe would be enriched with metals at different speeds. This may explain why astronomers see differing quantities of metals depending upon the direction in which they look.

However, if the fraction of escaping gas is really as low as XMM-Newton shows in NGC 4051, astronomers need to find another source of intergalactic metals. This might be the more prevalent star-forming galaxies called Ultra Luminous Infra Red Galaxies.

"Based on this one measurement, quasars can contribute some but not all of the metals to the intergalactic medium," says Krongold.

To continue the investigation, the astronomers will have to use the same XMM-Newton technique on a more powerful active galaxy. Such observations will allow them to determine whether the fraction of gas escaping changes or stays the same. If the fraction goes up, they will have solved the puzzle. If it stays the same, the search will have to continue.

The above results have been taken from the study 'The Compact, Conical, Accretion-Disk Warm Absorber of the Seyfert 1 Galaxy NGC 4051 and its Implications for IGM-Galaxy Feedback Processes' by Yair Krongold et al. Published 20 April, in the Astrophysical Journal.

SOURCE: SPACEFLIGHTNOW.COM
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Major Discovery: New Planet Could Harbor Water and Life
By Ker Than
Staff Writer
posted: 24 April 2007


An Earth-like planet spotted outside our solar system is the first found that could support liquid water and harbor life, scientists announced today.

Liquid water is a key ingredient for life as we know it. The newfound planet is located at the "Goldilocks" distance—not too close and not too far from its star to keep water on its surface from freezing or vaporizing away.

And while astronomers are not yet able to look for signs of biology on the planet, the discovery is a milestone in planet detection and the search for extraterrestrial life, one with the potential to profoundly change our outlook on the universe.

”The goal is to find life on a planet like the Earth around a star like the Sun. This is a step in that direction,” said study leader Stephane Udry of the Geneva Observatory in Switzerland. “Each time you go one step forward you are very happy.”

The new planet is about 50 percent bigger than Earth and about five times more massive. The new “super-Earth” is called Gliese 581 C, after its star, Gliese 581, a diminutive red dwarf star located 20.5 light-years away that is about one-third as massive as the Sun.

SOURCE: SPACE.COM
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Japan's asteroid explorer begins voyage back to Earth
BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: April 25, 2007

A small Japanese asteroid probe riddled by a streak of bad luck began its slow limp home Wednesday, but officials still face a myriad of challenges to bring the craft back in 2010.

Controllers sent commands for the Hayabusa probe to start one of its four ion engines Wednesday, officially beginning its three-year journey to Earth.

The milestone came after months of tests to determine whether the 900-pound spacecraft was healthy enough to attempt the voyage. Hayabusa is running on a damaged battery and just one of its four ion engines is currently deemed ready for long-term operations, according to the Japanese Aerospace Exploration Agency, or JAXA.

Hayabusa also lost two of its three fast-spinning reaction wheels responsible for attitude control. After the failures, the craft was forced to exhaust all of its chemical propellant reserves.

Engineers devised a new attitude control scheme using excess xenon fuel used by Hayabusa's electric propulsion system. Officials estimate Hayabusa's tanks still hold more than 66 pounds of xenon, while only about 44 pounds are needed for the Earth-bound leg of its mission.

JAXA officials remain cautious about the chances of Hayabusa successfully reaching Earth.

"This is not an optimistic operation, but a very tough operation," said Junichiro Kawaguchi, Hayabusa project manager, in a February interview. "The spacecraft is not in a very healthy state."

The probe is still located in the vicinity of asteroid Itokawa, a small potato-shaped space rock that was the subject of three months of scientific scrutiny by Hayabusa in 2005. Ground teams believe the spacecraft is currently about 50 million miles from Earth.

Hayabusa will have to complete two more orbits around the Sun before reaching Earth in June 2010, when it is expected to separate its return capsule for a parachuted landing in southern Australia.

The reentry vehicle was designed to house small chunks of Itokawa retrieved as Hayabusa swooped down to the surface of the asteroid. A small pellet was to fire into the asteroid to force dust and rocks into the sample chamber, but reviews of data streaming back from the spacecraft later caused engineers to question whether the system worked as planned.

Officials will likely not know for sure if the capsule contains any samples until it lands.

The start of the return trip was postponed by a year after a fuel leak in December 2005 threw Hayabusa off course and cut off communications with the probe for six weeks.

On Tuesday, JAXA released a heap of catalogued raw science data from Hayabusa's mission. The data included more than 1,600 optical images, about 135,000 pieces of spectral data in the near-infrared and X-ray bands, and 1.7 million data points from a laser rangefinder.

Scientists also assembled a three-dimensional shape video of Itokawa, which is believed to have been formed by the collection of several smaller bodies linked together by loose material and weak gravity.

SOURCE: SPACEFLIGHTNOW.COM
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Scientists discover vast intergalactic cloud of plasma
LOS ALAMOS NATIONAL LABORATORY NEWS RELEASE
Posted: April 30, 2007

LOS ALAMOS, New Mexico - Combining the world's largest radio telescope at Arecibo, Puerto Rico with a precision imaging, seven-antenna synthesis radio telescope at the Dominion Radio Astrophysical Observatory (DRAO), a team of researchers led by Los Alamos scientist Philipp Kronberg have discovered a new giant in the heavens, a giant in the form of a previously undetected cloud of intergalactic plasma that stretches more than 6 million light years across. The diffuse, magnetized intergalactic zone of high energy electrons may be evidence for galaxy-sized black holes as sources for the mysterious cosmic rays that continuously zip though the Universe. 

In research reported in the April issue of Astrophysical Journal, the team of researchers from Los Alamos, Arecibo, and DRAO in Penticton, British Columbia describe their discovery of a 2-3 megaparsec zone of diffuse, intergalactic plasma located beside the Coma cluster of galaxies. The combined use of the 305 meter Arecibo radio telescope to make a base scan of 50 square degrees of sky, and the DRAO, making 24 separate 12 hour observations over 24 days of the same sky area, resulted in an image comparable to that of a 1000 meter diameter radio telescope. After Arecibo mapped the larger cloud structure, DRAO data was used to enhance the resolution of the image. 

According to Kronberg, "One of the most exciting aspects of the discovery is the new questions it poses. For example, what kind of mechanism could create a cloud of such enormous dimensions that does not coincide with any single galaxy, or galaxy cluster? Is that same mechanism connected to the mysterious source of the ultra high energy cosmic rays that come from beyond our galaxy? And separately, could the newly discovered fluctuating radio glow be related to unwanted foregrounds of the Cosmic Microwave Background (CMB) radiation?" 

The synchrotron-radiating plasma cloud is spread across a vast region of space that may contain several black hole harboring radio galaxies. The cloud may be evidence that black holes in galaxies convert and transfer their enormous gravitational energy, by a yet unknown process, into magnetic fields and cosmic rays in the vast intergalactic regions of the Universe. 

Kronberg's work also provides the first preview of small (arc minute - level) features that could be associated with unwanted and confusing foregrounds to the CMB radiation. Because these same radiation frequencies are to be imaged by the PLANCK CMB Explorer, corrections to the observed CMB for foreground fluctuations (the so-called microwave "cirrus clouds") are vitally important to using CMB fluctuations as a probe of the early Universe. 

In addition to Kronberg, other members of the research team included, Roland Kothes from DRAO, and Christopher Salter and Phil Perillat from Arecibo and the National Astronomy and Ionosphere Center. The DRAO is operated by the Herzberg Institute of Astrophysics and the National Research Council of Canada. 

Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, BWX Technologies, and Washington Group International for the Department of Energy's National Nuclear Security Administration. 

Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.

SOURCE:SPACEFLIGHTNOW.COM
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Cosmologically speaking, diamonds may actually be forever
VANDERBILT UNIVERSITY NEWS RELEASE
Posted: April 30, 2007

NASHVILLE, Tenn. - If you've ever wondered about the ultimate fate of the universe, Lawrence Krauss and Robert Scherrer have some good news - sort of. 

In a paper published online on April 25 in the journal Physical Review D, the two physicists show that matter as we know it will remain as the universe expands at an ever-increasing clip. That is, the current status quo between matter and its alter ego, radiation, will continue as the newly discovered force of dark energy pushes the universe apart.

"Diamonds may actually be forever," quips Krauss, professor of physics and astronomy at Case Western Reserve University (CWRU) who is spending the year at Vanderbilt. "One of the only positive things that has arisen from the dark-energy dominated universe is that matter gets to beat radiation forever."

This viewpoint runs contrary to conventional wisdom among cosmologists. Today, there is more matter than radiation in the universe. But there were periods during the early universe that were dominated by radiation due to particle decays. The generally accepted view of the distant future has been that ordinary matter particles - protons and neutrons in particular - will gradually decay into radiation over trillions upon trillions of years, leaving a universe in which radiation once again dominates over matter; a universe lacking the material structures that are necessary for life.

It is only in the last decade that the existence of dark energy has been recognized. Before that Krauss and collaborators argued for its existence based on indirect evidence, but the first direct evidence came in 1998 when a major survey of exploding stars, called supernovae, revealed that the universe is apparently expanding at an increasing rate. Dark energy acts as a kind of anti-gravity that drives the expansion of the universe at large scales. Because it is associated with space itself, it is also called "vacuum energy." A number of follow-up observations have supported the conclusion that dark energy accounts for about 70 percent of all the energy in the universe.

"The discovery of dark energy has changed everything, but it has changed the view of the future more than the past. It is among the worst of all possible futures for life," says Krauss, who has spent the last few years exploring its implications. In an eternally expanding universe there is at least a chance that life could endure forever, but not in a universe dominated by vacuum energy, Krauss and CWRU collaborator Glenn Starkman have concluded. 

As the universe expands, the most distant objects recede at the highest velocity. The faster that objects recede, the more that the light coming from them is "red-shifted" to longer wavelengths. When their recessional velocity reaches light speed, they disappear because they are traveling away faster than the light that they emit. According to Krauss and Starkman, the process of disappearance has already begun: There are objects that were visible when the universe was half its present age that are invisible now. However, the process won't become really noticeable until the universe is about 100 billion years old. By ten trillion years, nothing but our local cluster of galaxies will be visible.

From the perspective of future civilizations, this process puts a finite limit on the amount of information and energy that will be available to maintain life. Assuming that consciousness is a physical phenomenon, this implies that life itself cannot be eternal, Krauss and Starkman argue. 

"Our current study doesn't change the process, but it does make it a little friendlier for matter and less friendly for radiation," says Scherrer, professor of physics at Vanderbilt. 

In their paper, Krauss and Scherrer analyzed all the ways that ordinary matter and dark matter could decay into radiation. (Dark matter is different from dark energy. It is an unknown form of matter that astronomers have only been able to detect by its gravitational effect on the ordinary matter in nearby galaxies. At this point, the physicists have no idea whether it is stable or will ultimately decay like ordinary matter.) Given known constraints on these various decay processes, the two show that none of them can produce radiation densities that exceed the density of the remaining matter. This is counter-intuitive because, when matter turns into energy, it does so according to Einstein's equation, E=mc2, and produces copious amounts of energy. 

"The surprising thing is that radiation disappears as fast as it is created in a universe with dark energy," says Krauss. 

The reason for radiation's vanishing act involves the expansion of space. Expanding space diminishes the density of radiant energy in two ways. The first is by increasing the separation between individual photons. The second is by reducing the amount of energy carried by individual photons. A photon's energy is contained entirely in its electromagnetic field. The shorter its wavelength and the higher its frequency, the more energy it contains. As space itself expands, the wavelengths of all the photons within it lengthen and their frequency drops. This means that the amount energy that individual photons contain also decreases. Taken together, these two effects dramatically reduce the energy density of radiation.

Protons and neutrons, by contrast, only suffer from the separation effect. Most of the energy that they carry is bound up in their mass and is not affected by spatial expansion. In an accelerating universe, that is enough of an advantage to maintain matter's dominance - forever. 

The research was funded by grants from the National Science Foundation and the U.S. Department of Energy. 

SOURCE:SPACEFLIGHTNOW.COM
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Astronomers discover a super-massive planet
HARVARD-SMITHSONIAN CENTER FOR ASTROPHYSICS NEWS RELEASE
Posted: May 2, 2007

CAMBRIDGE, MA - Today, astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) announced that they have found the most massive known transiting extrasolar planet. The gas giant planet, called HAT-P-2b, contains more than eight times the mass of Jupiter, the biggest planet in our solar system. Its powerful gravity squashes it into a ball only slightly larger than Jupiter.

HAT-P-2b shows other unusual characteristics. It has an extremely oval orbit that brings it as close as 3.1 million miles from its star before swinging three times farther out, to a distance of 9.6 million miles. If Earth's orbit were as elliptical, we would loop from almost reaching Mercury out to almost reaching Mars. Because of its orbit, HAT-P-2b gets enormously heated up when it passes close to the star, then cools off as it loops out again. Although it has a very short orbital period of only 5.63 days, this is the longest period planet known that transits, or crosses in front of, its host star.

"This planet is so unusual that at first we thought it was a false alarm - something that appeared to be a planet but wasn't," said CfA astronomer Gaspar Bakos. "But we eliminated every other possibility, so we knew we had a really weird planet."

Bakos is lead author of a paper submitted to the Astrophysical Journal describing the discovery.

HAT-P-2b orbits an F-type star, which is almost twice as big and somewhat hotter than the Sun, located about 440 light-years away in the constellation Hercules. Once every 5 days and 15 hours, it crosses directly in front of the star as viewed from Earth-a sort of mini-eclipse. Such a transit offers astronomers a unique opportunity to measure a planet's physical size from the amount of dimming.

Brightness measurements during the transit show that HAT-P-2b is about 1.18 times the size of Jupiter. By measuring how the star wobbles as the planet's gravity tugs it, astronomers deduced that the planet contains about 8.2 times Jupiter's mass. A person who weighs 150 pounds on Earth would tip the scale at 2100 pounds, and experience 14 times Earth's gravity, by standing on the visible surface (cloud tops) of HAT-P-2b.

CfA astronomer and co-author Robert Noyes said, "All the other known transiting planets are like 'hot Jupiters.' HAT-P-2b is hot, but it's not a Jupiter. It's much denser than a Jupiter-like planet; in fact, it is as dense as Earth even though it's mostly made of hydrogen."

"This object is close to the boundary between a star and a planet," said Harvard co-author Dimitar Sasselov. "With 50 percent more mass, it could have begun nuclear fusion for a short time."

An intriguing feature of HAT-P-2b is its highly eccentric (e=0.5) orbit. Gravitational forces between star and planet tend to circularize the orbit of a close-in planet. There is no other planet known with such an eccentric, close-in orbit. In addition, all other known transiting planets have circular orbits.

The most likely explanation is the presence of a second, outer world whose gravity pulls on HAT-P-2b and perturbs its orbit. Although existing data cannot confirm a second planet, they cannot rule it out either.

HAT-P-2b orbits the star HD 147506. With visual magnitude 8.7, HD 147506 is the fourth brightest star known to harbor a transiting planet, making the star (but not the planet) visible in a small, 3-inch telescope.

HAT-P-2b was discovered using a network of small, automated telescopes known as HATNet, which was designed and built by Bakos. The HAT network consists of six telescopes, four at the Smithsonian Astrophysical Observatory's Whipple Observatory in Arizona and two at its Submillimeter Array facility in Hawaii. As part of an international campaign, the Wise HAT telescope, located in the Negev desert (Israel) also took part in the discovery. The HAT telescopes conduct robotic observations every clear night, each covering an area of the sky 300 times the size of the full moon with every exposure. About 26,000 individual observations were made to detect the periodic dips of intensity due to the transit.

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Baby fish home in on mother's reef
It's a case of "reef, sweet reef" for baby tropical fish, say researchers who have found a way of tracking the movements of two generations of fish. Their study shows that baby fish are able to find their way home to the reef their mother lived on.

"We have suspected this for a long time," says Michael Berumen of the University of Arkansas in the US. "But it has spawned a big debate. We know fish are capable of returning to their home reef, but do they really? Until now, we didn't know the answer to that."

To see if this "self-recruitment" really does happen in the wild, Berumen and his colleagues in Australia and France travelled to Kimbe Island near Papua New Guinea. On the reef that surrounds the island (pictured, right), they collected 176 female clownfish and 123 female butterflyfish.

Clownfish spawn their eggs in a nest but the larvae can spend about 10 days floating around in open water before settling on a reef. Butterflyfish, like snappers, groupers and many other species targeted by the fisheries industry, are pelagic spawners – meaning they spray their eggs and sperm into open water. The juveniles do not settle on a reef until 38 days later.

Radioactive tag
The researchers injected both species with small amounts of a barium isotope. After travelling through the females' bloodstream, the radioactive tag ends up in their eggs and eventually in an ear bone in their offspring.

"It's a really neat technique that they've developed to actually tag fish through a whole reproductive season," says Stephen Simpson of Edinburgh University in the UK. "Particularly for a species of pelagic spawners whose eggs are much more difficult to find."

The scientists returned to the reef about one month after having released the tagged females and this time collected juveniles and counted how many carried the barium isotope. The team calculated that about 60% of the juveniles on the reef were the offspring of females from that reef.

"For pelagic spawners, this means the females spew their eggs into the water column and somehow the eggs hatch and the larvae find their way back to the reef, which they've never seen," says Simpson.

In the case of Butterflyfish, "there are 5 to 6 weeks during which they are potentially out at sea," says Berumen.

Smelly and noisy
How the fish find their way back to the reef is another question. According to Simpson, reef fish scientists have traditionally been divided between those who believe the dispersal of offspring is at the mercy of currents and those who believe it is driven by the behaviour of the offspring. He belongs to the second group and has shown that reef fish are capable of recognising the sound of their home reef. Other scientists have shown than fish can pick out their reef by its smell.

But where does this ability to sense the home reef come from? Simpson has a possible explanation: "You could imagine there is a suite of genes passed on to the embryos, who are therefore pre-programmed as to what they should do once their ears, eyes and nostrils develop".

The new research may not just be a curiosity. The knowledge of the area over which the reef fish travel could help design better marine reserves.

For example, the scientists say reserves that are too large may not enable fish from the protected areas to re-supply the surrounding areas, where fishing continues

http://environment.newscientist.com/article/dn11778-baby-fish-home-in-on-mothers-reef.html

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Red Orbit breaking News

http://www.redorbit.com/news/display/?id=747011

Posted on: Tuesday, 28 November 2006, 13:35 CST
Study Finds that a Single Impact Killed the Dinosaurs



Data supports the single-impact theory in a controversial discussion

COLUMBIA, Mo. – The dinosaurs, along with the majority of all other animal species on Earth, went extinct approximately 65 million years ago. Some scientists have said that the impact of a large meteorite in the Yucatan Peninsula, in what is today Mexico, caused the mass extinction, while others argue that there must have been additional meteorite impacts or other stresses around the same time.

A new study provides compelling evidence that "one and only one impact" caused the mass extinction, according to a University of Missouri-Columbia researcher.

"The samples we found strongly support the single impact hypothesis," said Ken MacLeod, associate professor of geological sciences at MU and lead investigator of the study. "Our samples come from very complete, expanded sections without deposits related to large, direct effects of the impact – for example, landslides – that can shuffle the record, so we can resolve the sequence of events well. What we see is a unique layer composed of impact-related material precisely at the level of the disappearance of many species of marine plankton that were contemporaries of the youngest dinosaurs. We do not find any sedimentological or geochemical evidence for additional impacts above or below this level, as proposed in multiple impact scenarios."

MacLeod and his co-investigators studied sediment recovered from the Demerara Rise in the Atlantic Ocean northeast of South America, about 4,500 km (approximately 2,800 miles) from the impact site on the Yucatan Peninsula. Sites closer to and farther from the impact site have been studied, but few intermediary sites such as this have been explored.

Interpretation of samples from locations close to the crater are complicated by factors such as waves, earthquakes and landslides that likely followed the impact and would have reworked the sediment. Samples from farther away received little impact debris and often don’t demonstrably contain a complete record of the mass extinction interval. The Demerara Rise samples, thus, provide an unusually clear picture of the events at the time of the mass extinction.

"With our samples, there just aren’t many complications to confuse interpretation. You could say that you’re looking at textbook quality samples, and the textbook could be used for an introductory class," MacLeod said. "It’s remarkable the degree to which our samples follow predictions given a mass extinction caused by a single impact. Sedimentological and paleontological complexities are minor, the right aged-material is present, and there is no support for multiple impacts or other stresses leading up to or following the deposition of material from the impact."

The impact of a meteorite on the Yucatan Peninsula likely caused massive earthquakes and tsunamis. Dust from the impact entered the atmosphere and blocked sunlight, causing plants to die and animals to lose important sources of food. Temperatures probably cooled significantly around the globe before warming in the following centuries, wildfires on an unprecedented scale may have burned and acid rain might have poured down.

MacLeod and many other scientists believe that these effects led to the relatively rapid extinction of most species on the planet. Some other scientists have argued that a single impact could not have caused the changes observed and say that the impact in the Yucatan predates the mass extinction by 300,000 years.

MacLeod’s co-investigators were Donna L. Whitney from the University of Minnesota, Brian T. Huber from the Smithsonian National Museum of Natural History and Christian Koeberl of the University of Vienna. The study was recently published in the ‘in press’ section of the online version of the Geological Society of America Bulletin. Funding was provided by the U.S. Science Support Program, the U.S. National Science Foundation and the Austrian Science Foundation. Samples were recovered on Leg 207 of the Ocean Drilling Program.

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Astronomers study a star born soon after the Big Bang
McDONALD OBSERVATORY NEWS RELEASE


AUSTIN ‹ How old are the oldest stars? An international team of astronomers led by Dr. Anna Frebel of The University of Texas at Austin McDonald Observatory recently measured the age of an ancient star in our Milky Way galaxy at an extraordinary 13.2 billion years. This measurement provides a lower limit to the age of the universe and will help to disentangle the chemical history of our galaxy. Frebel's results are published in today's edition of The Astrophysical Journal Letters.

The team used radioactive decay dating techniques to date the star, called HE 1523-0901. This is close to the age of the universe of 13.7 billion years. "This guy was born very shortly after the Big Bang," Frebel said.

"Surprisingly, it is very hard to pin down the age of a star," she said, "although we can generally infer that chemically primitive stars have to be very old." Such stars must have been born before many generations of stars had chemically enriched our galaxy.

Astronomers can only accurately measure the ages of very rare old stars that contain huge amounts of certain types of chemical elements, including radioactive elements like thorium and uranium.

Similar to the way archaeologists use carbon-14 and other elements to date Earth relics thousands of years old, astronomers use radioactive elements found in stars to deduce these stars' ages, which may be millions or billions of years.

"Very few stars display radioactive elements," Frebel said. "I'm looking at a very rare subgroup of these already rare stars. I'm looking for a needle in a haystack, really."

Frebel made the extremely difficult measurement of the amount of uranium in the star HE 1523-0901 using the UVES spectrograph on the Kueyen Telescope, one of four 8.2-meter telescopes that comprise The Very Large Telescope at the European Southern Observatory in Chile.

"This star is the best uranium detection so far," she said, explaining that while uranium has been discovered in two other stars previously, only one could be used to get a good age for the star. HE 1523-0901 also contains thorium, another radioactive element that is useful in age-dating of stars. Uranium, with a half-life of 4.5 billion years, is a better clock than thorium, Frebel says. Thorium's half-life of 14 billion years is actually longer than the age of the universe.

But astronomers need more than just radioactive elements like uranium and thorium to age-date a star. For each radioactive element, "you have to anchor it to another element within the star," Frebel said. Because she detected so many of these anchor elements in HE 1523-0901, she can come up with an extremely accurate age. In this case, the anchor elements are europium, osmium, and iridium.

The combination of two radioactive elements with three anchor elements discovered in this one star provided Frebel six so-called "cosmic clocks."

"So far, for no other star was it possible to employ more than one cosmic clock," she said. "Now we are suddenly provided with six measurements in just one star!"

How did she find this amazing star? Frebel says it was a case of "informed serendipity." She was researching a sample of old stars for her PhD thesis while a graduate student at The Australian National University, and recognized the consequences of this star's extraordinary spectrum after she measured it with ESO's Very Large Telescope.

"When you do discovery work, you never know what you're going to find," Frebel said. "You hope to find interesting objects. Depending on what you find, you then move in that direction."

The new result will be used by Frebel and her team to gain important clues to the creation and evolution of the chemical elements shortly after the Big Bang. It will also provide theorists with new, important experimental data. "Stars such as HE 1523-0901 are ideal cosmic laboratories to study nucleosynthesis," she said.

Frebel is now working with her colleagues Chris Sneden, Volker Bromm, Carlos Allende Prieto, Matthew Shetrone, and graduate student Ian Roederer at The University of Texas at Austin to further research extremely old stars with the 9.2-meter Hobby-Eberly Telescope at McDonald Observatory.

The Hobby-Eberly Telescope is a joint project of The University of Texas at Austin, The Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universitat Munchen and Georg-August-Unversitat Gottingen.

SOURCE:SPACEFLIGHTNOW.com
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Exotic extrasolar planet is the hottest yet discovered
UNIVERSITY OF CENTRAL FLORIDA NEWS RELEASE


ORLANDO - University of Central Florida Physics Professor Joseph Harrington and his team have measured the hottest planet ever at 3700 degrees Fahrenheit.

"HD 149026b is simply the most exotic, bizarre planet," Harrington said. "It's pretty small, really dense, and now we find that it's extremely hot."



 
 
Using Spitzer, NASA's infrared space telescope, Harrington and his team observed the tiny planet disappear behind its star and reappear. Although the planet cannot be seen separately from the star, the dimming of the light that reached Spitzer told the scientists how much light the hot planet emits. From this they deduced the temperature on the side of the planet facing its star. The team's findings were published online in Nature today.

Discovered in 2005, HD 149026b is a bit smaller than Saturn, making it the smallest extrasolar planet with a measured size. However, it is more massive than Saturn, and is suspected of having a core 70-90 times the mass of the entire Earth. It has more heavy elements (material other than hydrogen and helium) than exist in our whole solar system, outside the Sun.

There are more than 230 extrasolar planets, but this is only the fourth of these to have its temperature measured directly. It is simple to explain the temperatures of the other three planets. However, for HD 149026b to reach 3700 degrees, it must absorb essentially all the starlight that reaches it. This means the surface must be blacker than charcoal, which is unprecedented for planets. The planet would also have to re-radiate all that energy in the infrared.

"The high heat would make the planet glow slightly, so it would look like an ember in space, absorbing all incoming light but glowing a dull red," said Harrington.

Drake Deming, of NASA's Goddard Space Flight Center in Greenbelt, MD, and a co-author of the Nature paper, thinks theorists are going to be scratching their heads over this one. "This planet is off the temperature scale that we expect for planets, so we don't really understand what's going on," Deming said. "There may be more big surprises in the future."

Harrington's team on this project also included Statia Luszcz from the Center for Radiophysics and Space Research at Cornell University, who is now a graduate student at the University of California, Berkeley. Sara Seager, a theorist in the Departments of Earth, Atmospheric, and Planetary Sciences and of Physics at the Massachusetts Institute of Technology, and Jeremy Richardson, an observer from the Exoplanet and Stellar Astrophysics Laboratory at NASA Goddard, round out the team.

Harrington is no stranger to significant findings. His research was published in Science magazine in October 2006 and in Nature in February 2007. In the first of those papers, Harrington's team used Spitzer to make the first measurement of day and night temperature variation on a different extrasolar planet. That research found that a Jupiter-like gas-giant planet circling very close to its sun is as hot as fire on one side, and potentially as cold as ice on the other, a condition that may also hold for HD 149026b.

February's publication documented a landmark achievement. In a project led by Richardson, the group captured enough light from an exoplanet to spread it apart into a spectrum and find signatures of molecules in the planet's atmosphere -- a key step toward being able to detect life on alien worlds.

Harrington's team fared well in this year's stiff competition for observing time on NASA's orbiting infrared facility. They will observe HD 149026b using all of Spitzer's instruments in the coming year, to gain a better understanding of the planet's atmosphere. Harrington is a professor in UCF's growing program in planetary sciences.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center, Pasadena, Calif. JPL is a division of California Institute for Technology, Pasadena.
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Scientist finds a new way to the center of the Earth
NASA/JPL NEWS RELEASE


PASADENA, Calif. -- Humans have yet to see Earth's center, as did the characters in Jules Verne's science fiction classic, "Journey to the Center of the Earth." But a new NASA study proposes a novel technique to pinpoint more precisely the location of Earth's center of mass and how it moves through space.

Knowing the location of the center of mass, determined using measurements from sites on Earth's surface, is important because it provides the reference frame through which scientists determine the relative motions of positions on Earth's surface, in its atmosphere and in space. This information is vital to the study of global sea level change, earthquakes, volcanoes and Earth's response to the retreat of ice sheets after the last ice age.

The accuracy of estimates of the motion of Earth's center of mass is uncertain, but likely ranges from 2 to 5 millimeters (.08 to .20 inches) a year. Donald Argus of NASA's Jet Propulsion Laboratory, Pasadena, Calif., developed the new technique, which estimates Earth's center of mass to within 1 millimeter (.04 inches) a year by precisely positioning sites on Earth's surface using a combination of four space-based techniques. The four techniques were developed and/or operated by NASA in partnership with other national and international agencies. Results of the new study appear in the June issue of Geophysical Journal International.

Scientists currently define Earth's center in two ways: as the mass center of solid Earth or as the mass center of Earth's entire system, which combines solid Earth, ice sheets, oceans and atmosphere. Argus says there is room for improvement in these estimates.

"The past two international estimates of the motion of the Earth system's mass center, made in 2000 and 2005, differ by 1.8 millimeters (.07 inches) a year," he said. "This discrepancy suggests the motion of Earth's mass center is not as well known as we'd like."

Argus argues that movements in the mass of Earth's atmosphere and oceans are seasonal and do not accumulate enough to change Earth's mass center. He therefore believes the mass center of solid Earth provides a more accurate reference frame.

"By its very nature, Earth's reference frame is moderately uncertain no matter how it is defined," Argus said. "The problem is very much akin to measuring the center of mass of a glob of Jell-O, because Earth is constantly changing shape due to tectonic and climatic forces. This new reference frame takes us a step closer to pinpointing Earth's exact center."

Argus says this new reference frame could make important contributions to understanding global climate change. The inference that Earth is warming comes partly from observations of global sea level rise, believed to be due to ice sheets melting in Greenland, Antarctica and elsewhere. In recent years, global sea level has been rising faster, with the current rate at about 3 millimeters (.12 inches) a year. Uncertainties in the accuracy of the motion of Earth's center of mass result in significant uncertainties in measuring this rate of change.

"Knowing the relative motions of the mass center of Earth's system and the mass center of the solid Earth can help scientists better determine the rate at which ice in Greenland and Antarctica is melting into the ocean," Argus explained. He said the new frame of reference will improve estimates of sea level rise from satellite altimeters like the NASA/French Space Agency Jason satellite, which rely on measurements of the location and motion of the mass center of Earth's system.

"For scientists studying post-glacial rebound, this new reference frame helps them better understand how viscous [gooey or sticky] Earth's solid mantle is, which affects how fast Earth's crust rises in response to the retreat of the massive ice sheets that covered areas such as Canada 20,000 years ago," he said. "As a result, they'll be able to make more accurate estimates of these vertical motions and can improve model predictions."

Scientists can also use the new information to more accurately determine plate motions along fault zones, improving our understanding of earthquake and volcanic processes.

The new technique combines data from a high-precision network of global positioning system receivers; a network of laser stations that track high-orbiting geodetic satellites called Laser Geodynamics Satellites, or Lageos; a network of radio telescopes that measure the position of Earth with respect to quasars at the edge of the universe, known as very long baseline interferometry; and a French network of precise satellite tracking instruments called Doppler Orbit and Radiopositioning Integrated by Satellite, or DORIS.

JPL is managed for NASA by the California Institute of Technology in Pasadena.

SOURCE:SPACEFLIGHTNOW.com

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New research proves single origin of humans in Africa
New research published in the journal Nature (19 July) has proved the single origin of humans theory by combining studies of global genetic variations in humans with skull measurements across the world. The research, at the University of Cambridge and funded by the Biotechnology and Biological Sciences Research Council (BBSRC), represents a final blow for supporters of a multiple origins of humans theory.

Competing theories on the origins of anatomically modern humans claim that either humans originated from a single point in Africa and migrated across the world, or different populations independently evolved from homo erectus to home sapiens in different areas.

The Cambridge researchers studied genetic diversity of human populations around the world and measurements of over 6,000 skulls from across the globe in academic collections. Their research knocks down one of the last arguments in favour of multiple origins. The new findings show that a loss in genetic diversity the further a population is from Africa is mirrored by a loss in variation in physical attributes.

Lead researcher, Dr Andrea Manica from the University's Department of Zoology, explained: "The origin of anatomically modern humans has been the focus of much heated debate. Our genetic research shows the further modern humans have migrated from Africa the more genetic diversity has been lost within a population.

"However, some have used skull data to argue that modern humans originated in multiple spots around the world. We have combined our genetic data with new measurements of a large sample of skulls to show definitively that modern humans originated from a single area in Sub-saharan Africa."

The research team found that genetic diversity decreased in populations the further away from Africa they were - a result of 'bottlenecks' or events that temporarily reduced populations during human migration. They then studied an exceptionally large sample of human skulls. Taking a set of measurements across all the skulls the team showed that not only was variation highest amongst the sample from south eastern Africa but that it did decrease at the same rate as the genetic data the further the skull was away from Africa.

To ensure the validity of their single origin evidence the researchers attempted to use their data to find non-African origins for modern humans. Research Dr Francois Balloux explains: "To test the alternative theory for the origin of modern humans we tried to find an additional, non-African origin. We found this just did not work. Our findings show that humans originated in a single area in Sub-Saharan Africa."


SOURCE: EUREKALERT.ORG
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Supergiant star spews molecules needed for life
UNIVERSITY OF ARIZONA NEWS RELEASE
Posted: July 30, 2007

University of Arizona astronomers who are probing the oxygen-rich environment around a supergiant star with one of the world's most sensitive radio telescopes have discovered a score of molecules that include compounds needed for life.

"I don't think anyone would have predicted that VY Canis Majoris is a molecular factory. It was really unexpected," said Arizona Radio Observatory (ARO) Director Lucy Ziurys, UA professor of astronomy and of chemistry. "Everyone thought that the interesting chemistry in gas clouds around old stars was happening in envelopes around nearer, carbon-rich stars," Ziurys said. "But when we started looking closely for the first time at an oxygen-rich object, we began finding all these interesting things that weren't supposed to be there."

VY Canis Majoris, one of the most luminous infrared objects in the sky, is an old star about 5,000 light years away. It's a half million times more luminous than the sun, but glows mostly in the infrared because it's a cool star. It truly is "supergiant" -- 25 times as massive as the sun and so huge that it would fill the orbit of Jupiter. But the star is losing mass so fast that in a million years -- an astronomical eyeblink -- it will be gone. The star already has blown away a large part of its atmosphere, creating its surrounding envelope that contains about twice as much oxygen as carbon.

Ziurys and her colleagues are not yet halfway through their survey of VY Canis Majoris, but they've already published in the journal, Nature (June 28 issue), about their observations of a score of chemical compounds. These include some molecules that astronomers have never detected around stars and are needed for life.

Among the molecules Ziurys and her team reported in Nature are table salt (NaCl); a compound called phosphorus nitride (PN), which contains two of the five most necessary ingredients for life; molecules of HNC, which is a variant form of the organic molecule, hydrogen cyanide; and an ion molecule form of carbon monoxide that comes with a proton attached (HCO+). Astronomers have found very little phosphorus or ion molecule chemistry in outflows from cool stars until now.

"We think these molecules eventually flow from the star into the interstellar medium, which is the diffuse gas between stars. The diffuse gas eventually collapses into denser molecular clouds, and from these solar systems eventually form," Ziurys said.

Comets and meteorites dump about 40,000 tons of interstellar dust on Earth each year. We wouldn't be carbon-based life forms otherwise, Ziurys noted, because early Earth lost all of its original carbon in the form of a methane atmosphere.

"The origin of organic material on Earth -- the chemical compounds that make up you and me -- probably came from interstellar space. So one can say that life's origins really begin in chemistry around objects like VY Canis Majoris."

Astronomers previously studied VY Canis Majoris with optical and infrared telescopes. "But that's kind of like diving in with a butcher knife to look at what's there, when what you need is an oyster fork," Ziurys said.

The Arizona Radio Observatory's 10-meter Submillimeter Telescope (SMT) on Mount Graham, Ariz., excels as a sensitive stellar "oyster fork." Chemical molecules each possess their own unique radio frequencies. The astronomers identify the unique radio signatures of chemical compounds in laboratory work, enabling them to identify the molecules in space.

The ARO team recently began testing a new receiver in collaboration with the National Radio Astronomy Observatory. The receiver was developed as a prototype for the Atacama Large Millimeter Array, a telescope under construction in Chile. The state-of-the-art receiver has given the SMT 10 times more sensitivity at millimeter wavelengths than any other radio telescope. The SMT can now detect emission weaker than a typical light bulb from distant space at very precise frequencies.

The UA team has discovered that the molecules aren't just flowing out as a gas sphere around VY Canis Majoris, but also are blasting out as jets through the spherical envelope.

"The signals we receive show not only which molecules are seen, but how the molecules are moving toward and away from us," said Stefanie Milam, a recent doctoral graduate on the ARO team.

The molecules flowing out from VY Canis Majoris trace complex winds in three outflows: the general, spherical outflow from the star, a jet of material blasting out towards Earth, and another jet shooting out a 45 degree angle away from Earth.

Astronomers have seen bipolar outflows from stars before, but not two, unconnected, asymmetric and apparently random outflows, Ziurys said.

Ziurys said she believes the two random jets are evidence for what astronomers earlier proposed are "supergranules" that form in very massive stars, and has been seen in Betelgeuse. Supergranules are huge cells of gas that form inside the star, then float to the surface and are ejected out of the star, where they cool in space and form molecules, creating jet outflows with certain molecular compositions.

Back in the 1960s, no one believed molecules could survive the harsh environment of space. Ultraviolet radiation supposedly reduced matter to atoms and atomic ions. Now scientists conclude that at least half of the gas in space between the stars within the 33-light-year inner galaxy is molecular, Ziurys said. "Our results are more evidence that we live in a really molecular universe, as opposed to an atomic one," Ziurys said.

The Arizona Radio Observatory (ARO) owns and operates two radio telescopes in southern Arizona: The former NRAO 12 Meter (KP12m) Telescope located 50 miles southwest of Tucson on Kitt Peak and the Submillimeter Telescope (SMT) located on Mount Graham near Safford, Ariz. The telescopes are operated around-the-clock for about nine to 10 months per year for a combined 10,000 hours per observing season. About 1,500 hours are dedicated to sub-mm wavelengths at the SMT. The ARO offices are centrally located in the Steward Observatory building on the UA campus in Tucson.


SOURCE: http://spaceflightnow.com/news/n0707/30supergiant/
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Satellites unveil new type of active galaxy
NASA-GODDARD NEWS RELEASE
Posted: July 30, 2007

GREENBELT, Md. - An international team of astronomers using NASA's Swift satellite and the Japanese/U.S. Suzaku X-ray observatory has discovered a new class of active galactic nuclei (AGN).

By now, you'd think that astronomers would have found all the different classes of AGN - extraordinarily energetic cores of galaxies powered by accreting supermassive black holes. AGN such as quasars, blazars, and Seyfert galaxies are among the most luminous objects in our Universe, often pouring out the energy of billions of stars from a region no larger than our solar system. (NEIL EDIT: HOLY COW !!!!....that's well bright !!!)


But by using Swift and Suzaku, the team has discovered that a relatively common class of AGN has escaped detection...until now. These objects are so heavily shrouded in gas and dust that virtually no light gets out.

"This is an important discovery because it will help us better understand why some supermassive black holes shine and others don't," says astronomer and team member Jack Tueller of NASA's Goddard Space Flight Center in Greenbelt, Md.

Evidence for this new type of AGN began surfacing over the past two years. Using Swift's Burst Alert Telescope (BAT), a team led by Tueller has found several hundred relatively nearby AGNs that were previously missed because their visible and ultraviolet light was smothered by gas and dust. The BAT was able to detect high-energy X-rays from these heavily blanketed AGNs because, unlike visible light, high-energy X-rays can punch through thick gas and dust.

To follow up on this discovery, Yoshihiro Ueda of Kyoto University, Japan, Tueller, and a team of Japanese and American astronomers targeted two of these AGNs with Suzaku. They were hoping to determine whether these heavily obscured AGNs are basically the same type of objects as other AGN, or whether they are fundamentally different. The AGNs reside in the galaxies ESO 005-G004 and ESO 297-G018, which are about 80 million and 350 million light-years from Earth, respectively.

Suzaku covers a broader range of X-ray energies than BAT, so astronomers expected Suzaku to see X-rays across a wide swath of the X-ray spectum. But despite Suzaku's high sensitivity, it detected very few low- or medium-energy X-rays from these two AGN, which explains why previous X-ray AGN surveys missed them.

According to popular models, AGNs are surrounded by a donut-shaped ring of material, which partially obscures our view of the black hole. Our viewing angle with respect to the donut determines what type of object we see. But team member Richard Mushotzky, also at NASA Goddard, thinks these newly discovered AGN are completely surrounded by a shell of obscuring material. "We can see visible light from other types of AGN because there is scattered light," says Mushotzky. "But in these two galaxies, all the light coming from the nucleus is totally blocked."

Another possibility is that these AGN have little gas in their vicinity. In other AGN, the gas scatters light at other wavelengths, which makes the AGN visible even if they are shrouded in obscuring material.

"Our results imply that there must be a large number of yet unrecognized obscured AGNs in the local universe," says Ueda.

In fact, these objects might comprise about 20 percent of point sources comprising the X-ray background, a glow of X-ray radiation that pervades our Universe. NASA's Chandra X-ray Observatory has found that this background is actually produced by huge numbers of AGNs, but Chandra was unable to identify the nature of all the sources.

By missing this new class, previous AGN surveys were heavily biased, and thus gave an incomplete picture of how supermassive black holes and their host galaxies have evolved over cosmic history. "We think these black holes have played a crucial role in controlling the formation of galaxies, and they control the flow of matter into clusters," says Tueller. "You can't understand the universe without understanding giant black holes and what they're doing. To complete our understanding we must have an unbiased sample."

The discovery paper will appear in the August 1st issue of the Astrophysical Journal Letters.

SOURCE:http://spaceflightnow.com/news/n0707/30galaxy/
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Planet orbiting a giant red star discovered


A planet orbiting a giant red star has been discovered by an astronomy team led by Penn State's Alex Wolszczan, who in 1992 discovered the first planets ever found outside our solar system. The new discovery is helping astronomers to understand what will happen to the planets in our solar system when our Sun becomes a red-giant star, expanding so much that its surface will reach as far as Earth's orbit.

The star is 2 times more massive and 10 times larger than the Sun. The new planet circles the giant star every 360 days and is located about 300 light years from Earth, in the constellation Perseus. A paper describing the discovery will be published in a November 2007 issue of the Astrophysical Journal.

The discovery resulted from an ongoing effort that the research team began three years ago to find Jupiter-mass planets around red-giant stars that are typically farther from Earth than those included in most other planet searches.

"After astronomers have spent more than 10 years searching for planets around Sun-like stars and discovering over 250 planets elsewhere in our galactic neighborhood, we still do not know whether our solar system's properties, including life-supporting conditions on our planet, are typical or exceptional among solar systems throughout the Galaxy," Wolszczan says. "The picture for now, based on the searches for planets around stars like our Sun, is that our planetary system appears to be unusual in a number of ways."

"This planet is the first one discovered by Penn State astronomers with the Hobby-Eberly Telescope, and it is in one of the most distant of the ten published solar systems discovered around red-giant stars," comments Lawrence Ramsey, a member of the discovery team and the head of the Department of Astronomy and Astrophysics at Penn State. Ramsey is a leader in the conception, design, construction, and operation of the Hobby-Eberly Telescope. "We are now becoming serious participants in planetary searches and planetary astronomy using the Hobby-Eberly Telescope," he says.

Astronomers now are branching out with different strategies for searching for planets, with the hope of more quickly detecting life elsewhere in the universe, of discovering all the possible kinds of solar systems, and of learning how they form around different kinds of stars. Wolszczan's team used one of these new strategies -- searching for planets around giant stars, which have evolved to a later stage of life than our Sun's.

"We have compiled a catalog of nearly a thousand giant stars that are candidates for hosting solar systems," Wolszczan says.

Because the method for discovering planets involves repeated measurements of their gravitational effect on the star they circle, and because planets around red giants can take years to make one orbit around the star, the research team is just now beginning to reap discoveries from years of systematic observations.

"It took us 3 years to gather enough data on over 300 stars to start identifying those that are good candidates for having planetary companions," Wolszczan said. "This planet is just the first of a number of planet discoveries that this research program is likely to produce."

This research is a collaboration between astronomers at Penn State, Nicholas Copernicus University in Poland, the McDonald Observatory, and the California Institute of Technology.

"One important aspect of this work is that it marks the debut of a research group in Poland, led by Dr. Andrzej Niedzielski, which has become a serious contributor to discoveries in extra-solar planetary astronomy," Wolszczan said.

One reason for studying solar systems that include red-giant stars is that they help astronomers to understand more about the future of our own solar system -- as family photos can give children an idea of what they might look like when they are the age of their grandparents.

"Our Sun probably will make the Earth unhabitable in about 2 billion years because it will get hotter and hotter as it evolves on its way to becoming a red giant about 5 billion years from now," Wolszczan says.

As the star swells up, transforming itself into a red giant, it affects the orbits of its planets and the dynamics of the whole planetary system, causing such changes as orbit crossings, planet collisions, and the formation of new planets out of the debris of those collisions.

"When our Sun becomes a red giant, Earth and the other inner planets very likely will dive into it and disappear," Wolszczan says.

Another motivation for studying red-giant stars is to understand how their habitable zones move farther out as the star's radiating surface becomes bigger. Based on how long it took for life to develop on Earth, scientists speculate that there is more than enough time during a star's giant phase for life to get a start somewhere in the evolving habitable zones.

"In our solar system, places like Europa -- a satellite of Jupiter that now is covered by a thick layer of water ice -- might warm up enough to support life for more than a billion years or so, over the time when our Sun begins to evolve into a red giant, making life on Earth impossible," Wolszczan said.

The method the astronomers use to discover planets is to observe candidate stars, repeatedly measuring their space velocity using the Doppler effect -- the changes in the star's light spectrum that result from its being pulled alternately toward and away from Earth by the gravity of an orbiting planet.

"When we detect a significant difference in a star's velocity over a month or two, we then start observing that star more frequently," Wolszczan says. "In this paper, the velocity of the star changed by about 50 meters per second (about 100 miles per hour) between our first and second observations, so we observed that star more frequently and we found a clearly repeatable effect, indicating the presence of a planet." A star and its orbiting planet move around the center-of-mass of the whole system, so the star alternately approaches and recedes from Earth periodically. "When the star gets closer to us, its light becomes a little bit bluer and when it recedes from us, its light becomes redder, and we can measure that effect to deduce the presence of planets," Wolszczan explains.

Searching for planets around giant stars also is a clever way to learn about the formation of planets around stars more massive than our Sun. Because massive stars are so hot when they are in the phase of life of our Sun, astronomers have not been able to detect enough of their spectral lines to use the Doppler-spectroscopy method of finding planets. However, these stars become cooler as they evolve into giants, at which point the spectral-line observations needed for Doppler detection of planets become possible. "We want to know how often do planets form around stars that were more massive than our Sun," Wolszczan said. "Obviously, the more solar systems around red giants we discover and study, the better chance we have to really understand the big picture of planet formation."

Another reason astronomers are trying to discover planets around different kinds of stars at different stages of stellar evolution is to find out how different kinds of planetary systems change when their stars become red giants and how they ultimately end their lives as burnt-out, shrunken white-dwarfs.

"We really are at the very beginning of this effort and it is going to take time to get a consistent picture of planetary formation and evolution," Wolszczan says. "The more we learn, the greater the chance will be that sooner or later we will discover how ordinary or extraordinary is our home -- the Earth's solar system."

SOURCE: SPACEFLIGHTNOW.COM
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An Early Ape Shows Its Hand (8/8/07)

Fossils often have provided important insights into the evolution of humans and our ancestors. Even small fossils, such as bones from the hand or foot can tell us much about our ancestor’s and their behavior. Such may be the case with an ape that lived more than nine million years ago.

A study published in the latest journal issue of Proceedings of the Royal Society B: Biological Sciencesreports on the structure of the hand of Hispanopithecus, a critically important fossil from an ape that lived during the late Miocene of Spain. While the authors ponder that the fossil may be from a direct ancestor of living great apes (especially the orangutan), Dr. C. Owen Lovejoy, Kent State University Professor of Anthropology, suggests another possibility in his comment on the article published in the same issue.

A preeminent biological anthropologist in the study of human origins, Lovejoy suggests that the fossil may belong to an extinct ape with its own unique locomotor behavior—a special adaptation and unique form of locomtion that left no modern descendants.

In 2007, Lovejoy was elected to membership in the prestigious National Academy of Sciences for his excellence in original scientific research.

SOURCE:EUREKALERT.ORG
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Beyond Mesopotamia:

 A radical new view of human civilization reported in Science
Many urban centers crossed arc of Middle Asia 5,000 years ago

A radically expanded view of the origin of civilization, extending far beyond Mesopotamia, is reported by journalist Andrew Lawler in the 3 August issue of Science.

Mesopotamia is widely believed to be the cradle of civilization, but a growing body of evidence suggests that in addition to Mesopotamia, many civilized urban areas existed at the same time – about 5,000 years ago – in an arc that extended from Mesopotamia east for thousands of kilometers across to the areas of modern India and Pakistan, according to Lawler.

“While Mesopotamia is still the cradle of civilization in the sense that urban evolution began there,” Lawler said, “we now know that the area between Mesopotamia and India spawned a host of cities and cultures between 3000 B.C.E. and 2000 B.C.E.”

Evidence of shared trade, iconography and other culture from digs in remote areas across this arc were presented last month at a meeting in Ravenna, Italy of the International Association for the Study of Early Civilizations in the Middle Asian Intercultural Space. The meeting was the first time that many archaeologists from more than a dozen countries gathered to discuss the fresh finds that point to this new view of civilization’s start. Science’s Lawler was the only journalist present.

Archaeologists shared findings from dozens of urban centers of approximately the same age that existed between Mesopotamia and the Indus River valley in modern day India and Pakistan. The researchers are just starting to sketch out this new landscape, but it’s becoming clear that these centers traded goods and could have shared technology and architecture. Recovered artifacts such as beads, shells, vessels, seals and game boards show that a network linked these civilizations.

Researchers have also found hints, such as similar ceremonial platforms, that these cultures interacted and even learned from one another. A new excavation near Jiroft in southeastern Iran, for example, has unearthed tablets with an unknown writing system. This controversial find highlights the complexity of the cultures in an area long considered a backwater, Lawler explained.

These urban centers are away from the river valleys that archaeologists have traditionally focused on, according to Lawler. Archaeologists now have access to more remote locations and are expanding their studies.

SOURCE:EUREKALERT.ORG
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