[neilep]

A Fire Rainbow Over New Jersey
Credit & Copyright: Paul Gitto (Arcturus Observatory)


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What is that inverted rainbow in the sky? Sometimes known as a fire rainbow for its flame-like appearance, a circumhorizon arc is created by ice, not fire. For a circumhorizon arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds are present. Furthermore, the numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight like a single gigantic prism. Therefore, circumhorizon arcs are quite unusual to see. Pictured above, however, a rare fire rainbow was captured above trees in Whiting, New Jersey, USA in late May.

[neilep]

BLAST OFF
Image Credit: Jerry Cannon, Robert Murray, NASA

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Rising through a billowing cloud of smoke, this Delta II rocket left Cape Canaveral Air Force Station's launch pad 17-B Wednesday at 12:05 pm EDT. Snug in the payload section was GLAST, the Gamma-ray Large Area Space Telescope, now in orbit around planet Earth. GLAST's detector technology was developed for use in terrestrial particle accelerators. But from orbit, GLAST can study gamma-rays from extreme environments in our own Milky Way galaxy, as well as supermassive black holes at the centers of distant active galaxies, and the sources of powerful gamma-ray bursts. Those cosmic accelerators achieve energies not attainable in earthbound laboratories. GLAST also has the sensitivity to search for signatures of new physics in the relatively unexplored high-energy gamma-ray regime.

[neilep]

Pluto assigned 'plutoid' tag
 in new IAU classification
BY DR EMILY BALDWIN
ASTRONOMY NOW
Posted: June 12, 2008

Almost two years after the International Astronomical Union (IAU) caused a worldwide furore by stripping Pluto of its former status as a 'proper' planet to a dwarf planet, the term 'plutoid' has been introduced to describe "Pluto-like transneptunian dwarf planets".


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The IAU's new Solar System, as defined in 2006,
 with Pluto, Eris and Ceres named as dwarf planets.
 Now, Pluto and Eris are plutoids, while Ceres
 remains a dwarf planet. Image: IAU.

The original demotion of Pluto to a dwarf planet came about as a result of numerous discoveries of Pluto-like bodies, some even larger in size, in the far reaches of our Solar System. If they were treated the same as Pluto, they too would have to be called planets, taking the Solar System’s planet inventory to more than 50, a prospect that was even less favourable than relegating just one planet to a sub-category, which also included the bodies Ceres and Eris.

Now, the IAU have once again re-written the textbooks to introduce a new term – 'plutoid' – to describe “celestial bodies in orbit around the Sun at a distance greater than that of Neptune, that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a near-spherical shape, and that have not cleared the neighbourhood around their orbit of debris”. The body must also have an absolute magnitude brighter than +1 to be considered as a plutoid and be named by the IAU as one. If, subsequently, the plutoid candidate turns out to not be massive enough to be classified as one, it will still keep its name, but will change category.


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The new plutoid category of Solar System bodies
 includes Pluto and its moons Charon, Hydra and
 Nix (left) and Eris and its moon Dysnomia (right)
. Image: IAU.

The new classification systems means that while Pluto and Eris are the first plutoids of the Solar System, Ceres remains a dwarf planet, because it is located in the asteroid belt between Mars and Jupiter. It is expected that more plutoids will be named as science progresses and new discoveries are made.

[neilep]

M51 Hubble Remix
Credit: S. Beckwith (STScI),
 Hubble Heritage Team, (STScI/AURA), ESA, NASA
Additional Processing: Robert Gendler



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 The 51st entry in Charles Messier's famous catalog is perhaps the original spiral nebula - a large galaxy with a well defined spiral structure also cataloged as NGC 5194. Over 60,000 light-years across, M51's spiral arms and dust lanes clearly sweep in front of its companion galaxy (right), NGC 5195. Image data from the Hubble's Advanced Camera for Surveys has been reprocessed to produce this alternative portrait of the well-known interacting galaxy pair. The processing has further sharpened details and enhanced color and contrast in otherwise faint areas, bringing out dust lanes and extended streams that cross the small companion, along with features in the surroundings and core of M51 itself. The pair are about 31 million light-years distant. Not far on the sky from the handle of the Big Dipper, they officially lie within the boundaries of the small constellation Canes Venatici.

[neilep]

Phoenix Digs for Clues on Mars
Credit: Phoenix Mission Team, NASA,
 JPL-Caltech, U. Arizona, Texas A&M University


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 What's a good recipe for preparing Martian soil? Start by filling your robot's scoop a bit less than half way. Next, dump your Martian soil into one of your TEGA ovens, being sure to watch out for clumping. Then, slowly increase the temperature to over 1000 degrees Celsius over several days. Keep checking to see when your soil becomes vaporized. Finally, your Martian soil is not ready for eating, but rather sniffing The above technique is being used by the Phoenix Lander that arrived on Mars three weeks ago. Data from the first batch of baked soil should be available in a few days. Pictured above, a circular array of the Phoenix Lander's solar panels are visible on the left, while a scoop partly filled with Martian soil is visible on the right. The robotic Phoenix Lander will spend much of the next three months digging, scooping, baking, sniffing, zapping, dissolving, and magnifying bits of Mars to help neighboring Earthlings learn more about the hydrologic and biologic possibilities of the sometimes mysterious red planet.

[neilep]

Eta Carinae and the Homunculus Nebula
Credit: N. Smith, J. A. Morse (U. Colorado) et al., NASA

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 How did the star Eta Carinae create this unusual nebula? No one knows for sure. About 165 years ago, the southern star Eta Carinae mysteriously became the second brightest star in the night sky. In 20 years, after ejecting more mass than our Sun, Eta Car unexpected faded. This outburst appears to have created the Homunculus Nebula, pictured above in a composite image from the Hubble Space Telescope taken last decade. Visible in the above image center is purple-tinted light reflected from the violent star Eta Carinae itself. Surrounding this star are expanding lobes of gas laced with filaments of dark dust. Jets bisect the lobes emanating from the central star. Surrounding these lobes are red-tinted debris captured only by its glow in a narrow band of red light. This debris is expanding most quickly of all, and includes streaming whiskers and bow shocks caused by collisions with previously existing material. Eta Car still undergoes unexpected outbursts, and its high mass and volatility make it a candidate to explode in a spectacular supernova sometime in the next few million years.

[neilep]

Pickering's Triangle from Kitt Peak
Credit & Copyright: T. Rector (U. Alaska Anchorage), H. Schweiker, WIYN, NOAO, AURA, NSF

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Biggy Piccy Here...it's worth it !!

 Wisps like this are all that remain visible of a Milky Way star. About 7,500 years ago that star exploded in a supernova leaving the Veil Nebula, also known as the Cygnus Loop. At the time, the expanding cloud was likely as bright as a crescent Moon, remaining visible for weeks to people living at the dawn of recorded history. Today, the resulting supernova remnant has faded and is now visible only through a small telescope directed toward the constellation of Cygnus. The remaining Veil Nebula is physically huge, however, and even though it lies about 1,400 light-years distant, it covers over five times the size of the full Moon. In images of the complete Veil Nebula, studious readers should be able to identify the Pickering's Triangle component pictured above, a component named for a famous astronomer and the wisp's approximate shape. The above image is a mosaic from the 4-meter Mayall telescope at the Kitt Peak National Observatory located in Arizona, USA.

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Shadow of a Martian Robot
Credit: Mars Exploration Rover Mission, JPL, NASA


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What if you saw your shadow on Mars and it wasn't human? Then you might be the Opportunity rover currently exploring Mars. Opportunity and sister robot Spirit have been probing the red planet since early 2004, finding evidence of ancient water, and sending breathtaking images across the inner Solar System. Pictured above, Opportunity looks opposite the Sun into Endurance Crater and sees its own shadow. Two wheels are visible on the lower left and right, while the floor and walls of the unusual crater are visible in the background. Opportunity and Spirit have now spent over four years exploring the red world, find new clues into the wet ancient past of our Solar System's second most habitable planet.

[neilep]

The tiny star with a monster roar
BY DR EMILY BALDWIN
ASTRONOMY NOW
Posted: May 20, 2008

The brightest flare ever seen from a normal star other than our Sun, worth thousands of solar flares, has been released from a star that shines with just one percent of the Sun’s light.

EV Lacertae is a fairly normal red dwarf, the most common type of star in the Universe, and is one of our closest stellar neighbours at a distance of just 16 light-years. But weighing in at less than one-third the mass of the Sun and offering a faint magnitude 10 glow, it is far below naked eye visibility. That is, until it released a monster flare, detected on April 25 by the Russian-built Konus instrument on NASA’s Wind satellite and followed up by the Swift satellite, that would have been easily visible with the naked eye if the star had been observable in the night sky at the time. The flare remained bright in X-rays for eight hours before settling back to normal and was so blinding it caused instruments onboard Swift to automatically shut down.


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An artist impression of the incredibly powerful
 flare that erupted from the red dwarf star EV
 Lacertae last month. Image: Casey Reed/NASA.

"This gives us a golden opportunity to study a stellar flare on a second-by-second basis to see how it evolved," says Stephen Drake of NASA Goddard.

EV Lacertae rotates once every four days, generating strong localised magnetic fields that make it over one hundred times as magnetically powerful as the Sun’s field. The energy stored in its magnetic field powers the giant flares. The star is also a youthful few hundred million years old, around 15 times younger than our Sun. Younger stars rotate faster and generate more powerful flares, so in its first billion years our own Sun must have let loose millions of energetic flares that would have profoundly affected Earth and the other planets.

"Flares like this would deplete the atmospheres of life-bearing planets, sterilising their surfaces," says Rachel Osten, a Hubble Fellow at the University of Maryland and NASA Goddard.

Because of EV Lacertae’s relative youth, studying this recent eruption will give scientists a window into our Solar System’s early history.

 

[neilep]

Galaxy Zoo’s special exhibition of merging galaxies
BY DR EMILY BALDWIN
ASTRONOMY NOW
Posted: May 19, 2008

Since Galaxy Zoo opened its gates almost a year ago, over 125,000 armchair astronomers have visited the online menagerie and made around 40,000,000 individual classifications of elliptical, spiral and merging galaxies. Now the team are appealing to the public to review their set of possible merging galaxies in order to answer some long standing questions about the weird and wonderful world of interacting galaxies.

As with any zoo the oddest creations provide the greatest thrill, and Galaxy Zoo is no exception. From the original classifications, the results of which were recently submitted to peer reviewed journals, a fantastic set of merging galaxies have been identified. The Galaxy Zoo team are now relying on the public to review the set of possible merging galaxies, in order to make sure the team have as many true merger candidates as possible, therefore maximising the pool of scientific data to work with. The results will help to answer some of the long standing questions surrounding the importance and frequency of merging galaxies.

In theoretical simulations, astronomers have found that the merger of spiral galaxies can create an elliptical galaxy, and that an elliptical can become a spiral by accretion of further stars and gas during its lifetime. Since Edwin Hubble first devised the galaxy classification system, which divided galaxies into two main categories – rugby ball shaped ‘elliptical’ galaxies and whirlpool like ‘spiral’ galaxies – there has been controversy among scientists about how these two principal types are even connected in the global understanding of galaxy formation and evolution. By classifying some of these images visitors are helping astronomers to understand the structure of the Universe and how galaxies form and evolve.

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The work of the Galaxy Zoo team, and of the interested public, is far from done: Galaxy Zoo 2’s development is well under way, which will see a much more detailed classification system of the brightest galaxies in the Sloan Digital Sky Survey, an ambitious astronomical survey which is systematically mapping a quarter of the entire sky. Even further down the line we will see Galaxy Zoo 3 with brand new data. The ultimate goal of Galaxy Zoo is to perform a census of the one million galaxies captured by the Sloan Digital Sky Survey.

To find instructions on how to contribute to the Galaxy Zoo survey, including an interactive tutorial to teach you how to classify the galaxies, visit www.galaxyzoo.org, but be warned, it’s highly addictive!

 

[neilep]

New red spot appears on Jupiter
BY DR EMILY BALDWIN
ASTRONOMY NOW
Posted: May 23, 2008

In what is beginning to look like a case of planetary measles, a third red spot has appeared alongside the Great Red Spot and Red Spot Junior in the turbulent Jovian atmosphere.

Jupiter has spawned a third, smaller, red oval in the same band of clouds as its big brother, the Great Red Spot (GRS). The new addition to the family was previously a white shaped oval storm; the change to a red colour indicates its swirling storm clouds are rising to heights like the clouds of its siblings, according to detailed analysis of the visible-light images taken by Hubble's Wide Field Planetary Camera 2 on May 9 and 10, and near-infrared adaptive optics images taken by the W.M. Keck telescope on May 11.


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The new observations support the idea that Jupiter is in the midst of global climate change, as first proposed by Professor Phil Marcus at the University of California in 2004, causing temperatures to change by about 10 degrees Celsius, getting warmer near the equator and cooler near the south pole. Marcus predicted that large changes would start in the southern hemisphere around 2006, causing the jet streams to become unstable and spawn new vortices, just as has been observed.


"The appearance of the planet's cloud system from just north of the equator down to 34 degrees south latitude keeps surprising us with changes and, in particular, with new cloud features that haven't been previously observed," says Marcus. "Whether or not Jupiter's climate has changed due to a predicted warming, the cloud activity over the last two and a half years shows dramatically that something unusual has happened."

The original two red spots are squeezed between bands called shear flows, where the flow above each storm is moving westward and the flow below is moving eastward. Since the shear flow in each band is slightly different, and the storms are different sizes, the GRS drifts in a westward direction while the Little Red Spot drifts eastward. The result is that the storms pass each other roughly every two years, with the next close encounter in June. But, because the new red spot is located in the same band of clouds as the GRS, if the two storms continue on their present courses they will collide in August, and the small oval will either be be consumed or repelled by Jupiter's persistent GRS.

 

[neilep]

NGC 7331 and Beyond
Credit & Copyright: Don Goldman, Sierra Remote Observatories


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Big, beautiful spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. Since the galaxy's disk is inclined to our line-of-sight, long telescopic exposures often result in an image that evokes a strong sense of depth. The effect is further enhanced in this well-framed view by the galaxies that lie beyond this gorgeous island universe. The background galaxies are about one tenth the apparent size of NGC 7331 and so lie roughly ten times farther away. Their strikingly close alignment on the sky with NGC 7331 occurs just by chance. The visual grouping of galaxies is also known as the Deer Lick Group.

[neilep]

A Dark Sky Over Death Valley
Credit: Dan Duriscoe, U.S. National Park Service



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 This eerie glow over Death Valley is in danger. Scrolling right will show a spectacular view from one of the darkest places left in the continental USA: Death Valley, California. The above 360-degree full-sky panorama is a composite of 30 images taken two years ago in Racetrack Playa. The image has been digitally processed and increasingly stretched at high altitudes to make it rectangular. In the foreground on the image right is an unusually placed rock that was pushed by high winds onto Racetrack Playa after a slick rain. In the background is a majestic night sky, featuring thousands of stars and many constellations. The arch across the middle is the central band of our Milky Way Galaxy. Light pollution is threatening dark skies like this all across the US and the world, and therefore the International Dark-Sky Association and the US National Parks Service are suggesting methods that can protect them.

[neilep]

Gas and Dust of the Lagoon Nebula
Credit & Copyright: Fred Vanderhaven



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Nice eh ?...Being delivered next Tuesday !!





This beautiful cosmic cloud is a popular stop on telescopic tours of the constellation Sagittarius. Eighteenth century cosmic tourist Charles Messier cataloged the bright nebula as M8, while modern day astronomers recognize the Lagoon Nebula as an active stellar nursery about 5,000 light-years distant, in the direction of the center of our Milky Way Galaxy. Striking details can be traced through this remarkable picture, processed to remove stars and hence better reveal the Lagoon's range of filaments of glowing hydrogen gas, dark dust clouds, and the bright, turbulent hourglass region near the image center. This color composite view was recorded under dark skies near Sydney, Australia. At the Lagoon's estimated distance, the picture spans about 50 light-years.

[neilep]

Extra Galaxies
Credit & Copyright: Dietmar Hager




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A careful look at the full field of view for this sharp image reveals a surprising number of galaxies both near and far toward the constellation Ursa Major. The most striking is clearly NGC 3718, the warped spiral galaxy right of center. NGC 3718's faint spiral arms look twisted and extended, its bright central region crossed by obscuring dust lanes. A mere 150 thousand light-years to the left is another large spiral galaxy, NGC 3729. The two are likely interacting gravitationally, accounting for the peculiar appearance of NGC 3718. While this galaxy pair lies about 52 million light-years away, the remarkable Hickson Group 56 can also be seen clustered just below NGC 3718. Hickson Group 56 consists of five interacting galaxies and lies over 400 million light-years away.

[neilep]

Fossil feathers preserve evidence of color

.......say Yale scientists





New Haven, Conn. — The traces of organic material found in fossil feathers are remnants of pigments that once gave birds their color, according to Yale scientists whose paper in Biology Letters opens up the potential to depict the original coloration of fossilized birds and their ancestors, the dinosaurs.

Closer study of a number of fossilized bird feathers by Yale PhD student Jakob Vinther revealed that organic imprints in the fossils — previously thought to be carbon traces from bacteria — are fossilized melanosomes, the organelles that contain melanin pigment.


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"Birds frequently have spectacularly colored plumage which are often used in camouflage and courtship display," said Vinther. "Feather melanin is responsible for rusty-red to jet-black colors and a regular ordering of melanin even produces glossy iridescence. Understanding these organic remains in fossil feathers also demonstrates that melanin can resist decay for millions of years."

Working with Yale paleontologist Derek E. G. Briggs and Yale ornithologist Richard O. Prum, Vinther analyzed a striped feather found in 100 million-year-old rocks from the Lower Cretaceous Period in Brazil. The team used a scanning electron microscope to show that dark bands of the feather preserved the arrangement of the pigment-bearing structures as a carbon residue — organized much as the structures are in a modern feather. The light bands showed only rock surface.

In another fossil of a bird from the Eocene Epoch — 55 million years ago — in Denmark there were similar traces in the feathers surrounding the skull. That fossil also preserved an organic imprint of the eye and showed structures similar to the melanosomes found in eyes of modern birds.
Jacob Vinther


"Many other organic remains will presumably prove to be composed of melanin," said Vinther. He expects that fur of ancient mammals and skin from dinosaurs preserved as organic imprints will likely be the remains of the melanin.

"Now that we have demonstrated that melanin can be preserved in fossils, scientists have a way to reliably predict, for example, the original colors of feathered dinosaurs," said Prum, who is the William Robertson Coe Professor of Ornithology and chair of the Department of Ecology and Evolutionary Biology, as well as curator of ornithology at Yale's Peabody Museum of Natural History.

[neilep]

Jupiter over Ephesus
Credit & Copyright: Tunç Tezel (TWAN)


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 A brilliant Jupiter shares the sky with the Full Moon tonight. Since Jupiter is near opposition, literally opposite the Sun in planet Earth's sky, Jupiter will rise near sunset just like the Full Moon. Of course, opposition is also the point of closest approach, with Jupiter shining at its brightest and offering the best views for skygazers. Recorded late last month, this moving skyscape features Jupiter above the southeastern horizon and the marbled streets of the ancient port city of Ephesus, located in modern day Turkey. At the left is a temple dedicated to the Roman emperor Hadrian. The beautiful night sky also includes the arc of the northern summer Milky Way. Lights on the horizon are from the nearby town of Selçuk. Clicking on the image will download the scene as a panorama.

[neilep]

M16 and the Eagle Nebula
Credit & Copyright: Johannes Schedler (Panther Observatory)



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Young star cluster M16 is surrounded by natal clouds of cosmic dust and glowing gas also known as The Eagle Nebula. This beautifully detailed image of the region includes fantastic shapes made famous in well-known Hubble Space Telescope close-ups of the starforming complex. Described as elephant trunks or Pillars of Creation, dense, dusty columns rising near the center are light-years in length but are gravitationally contracting to form stars. Energetic radiation from the cluster stars erodes material near the tips, eventually exposing the embedded new stars. Extending from the upper left edge of the nebula is another dusty starforming column known as the Fairy of Eagle Nebula. M16 and the Eagle Nebula lie about 7,000 light-years away, an easy target for binoculars or small telescopes in a nebula rich part of the sky toward the split constellation Serpens Cauda (the tail of the snake).

[neilep]

Crescent Rhea Occults Crescent Saturn
Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA



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Soft hues, partially lit orbs, a thin trace of the ring, and slight shadows highlight this understated view of the majestic surroundings of the giant planet Saturn. Looking nearly back toward the Sun, the robot Cassini spacecraft now orbiting Saturn captured crescent phases of Saturn and its moon Rhea in color a few years ago. As striking as the above image is, it is but a single frame from a recently released 60-frame silent movie where Rhea can be seen gliding in front of its parent world. Since Cassini was nearly in the plane of Saturn's rings, the normally impressive rings are visible here only as a thin line across the image center. Although Cassini has now concluded its primary mission, its past successes and opportunistic location have prompted NASA to start a two-year Equinox Mission, further exploring not only Saturn's enigmatic moons Titan and Enceladus, but Saturn herself as her grand rings tilt right at the Sun in August 2009.

[RD]

NASA has released images of the Moon taken from its Deep Impact spacecraft - some 31 million miles from Earth.

A camera on the probe was turned back towards Earth and in a time lapse sequence, captured the moon passing in front on 29 May.

The video shows a graphic, in the corner, highlighting the position of the earth at the time of the image.

http://news.bbc.co.uk/1/hi/sci/tech/7515249.stm