[neilep]

Spitzer glimpses into
Milky Way outback
DR EMILY BALDWIN
ASTRONOMY NOW


New images from the Spitzer Space Telescope survey GLIMPSE360 have revealed a treasure trove of gems scattered around the suburbs of the Milky Way, including some unexpectedly massive young stars.

The new survey is an extension of the original GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire) that focused on the Galaxy's bustling hub of stars and black hole embedded in the centre. Now the attention shifts to the suburbs, where the remaining half of the Milky Way's disc out to its edge will fall under scrutiny.

"It's like looking into the wilderness of our Galaxy," says Barbara Whitney, principal investigator for the survey. "While mapping the stars and dust out there, we hope to answer some major questions about an environment that is very different from the inner Milky Way."


Image: NASA/JPL-Caltech/2MASS/B. Whitney (SSI/University of Wisconsin).

One of the questions to be answered is how stars can be born in these distal regions that have a lower concentration of star-forming ingredients than the centre of the Galaxy. For example, in the image above, star-forming region BG2107+49 hosts swarms of young stars in the making that are ten to twenty times the mass of our own Sun.



Image: NASA/JPL-Caltech/2MASS/B. Whitney (SSI/University of Wisconsin).

The new images are permeated with a greenish mist that is rich in hydrogen and carbon compounds called polycyclic aromatic hydrocarbons (PAHs). PAHs are found on the Earth in sooty vehicle exhausts and on charred grills, but in space, they lurk in dark clouds that spawn stars. Of course they are not really green, the colour is added to bring out the glow that is only visible in infrared wavelengths. One particular snap shot (above) is defined by the streaks of dust grains across the star in the upper left, that are likely aligned with the magnetic field of the star. Around the star that lies in the centre of the image, GL 490, several dense clumps of gas have been identified; these give away the locations of the youngest large stars that will help astronomers learn more about the earliest stages of massive star formation.


Image: NASA/JPL-Caltech/2MASS/B. Whitney (SSI/University of Wisconsin).

In another image (above), an outflow of gas from a new star in a region known as IRAS 21078+5211 is seen ramming into the surrounding hydrogen gas to make it glow. The survey will help detail the structure of the outer Galaxy and try and determine where there Milky Way meets the void of intergalactic space.

GLIMPSE360 began last September and will continue through to the start of 2011, with data processing expected to take another year. Once the full survey is complete and combined with the previous GLIMPSE and GIMPSE3D data, it will provide a 360 degree field-of-view of the Galaxy, ranging in height from 2.7 degrees to 8.4 degrees at the centre.

"We look forward to what GLIMPSE360 will show us," Whitney says. "The adventure is just getting started."

[neilep]

ISS, Moon, Planets, and Pyramids

Photographer: Aymen Ibrahem
Summary Author: Aymen Ibrahem; Jim Foster



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The photo above showing the International Space Station (ISS), the waxing Moon and several planets parading across the summer sky was captured from the Plateau of Giza, Egypt on July 16, 2010. Venus, just above the Second Pyramid (Chephren), is the brightest object other than the nearly half lit Moon. Saturn is above and to the right of the Moon, and coppery Mars lies in between Venus and Saturn. All are in the plane of the ecliptic, which happens to be almost perpendicular to the side face of Chephren. For a few days after this photo was taken, these three planets were in very close proximity to one another in the western sky. Note that the Sphinx and pyramids are bathed in blue and green light as part of nightly laser displays.

[neilep]

The Blazing Beauty of the Small Magellanic Cloud & Beyond


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At the remote outskirts of the Small Magellanic Cloud, a satellite galaxy some 200 thousand light-years distant, lies the young 5-million-year-old star cluster NGC 602, surrounded by natal gas and dust. Fantastic ridges and swept back shapes strongly suggest that energetic radiation and shock waves from NGC 602's massive young stars have eroded the dusty material and triggered a progression of star formation moving away from the cluster's center. At the estimated distance of the Small Magellanic Cloud, the picture spans about 200 light-years, including a cosmic assortment of background galaxies hundreds of millions of light-years or more beyond.


Credit: NASA, ESA, and the Hubble Heritage Team (STScI / AURA) - ESA/Hubble Collaboration

[neilep]

SPOTTED LAKE
Photographer: Chris Gozdzik
Summary Author: Chris Gozdzik; Jim Foster



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The photo above shows enigmatic Spotted Lake near Osoyoos, British Columbia. It could also be called "Doubletake Lake" since that's likely what many people do when they witness this odd body of "water." Its spots result from a high concentration of a number of different minerals, including magnesium sulfate, calcium and sodium sulfates. At least a dozen other minerals are found in the lake's water in varying concentrations. By late summer, much of the water evaporates and only a mineral stew remains. It's primarily crystals of magnesium sulfate that contributes to the spotty appearance. Different minerals yield different colors. Spotted Lake was once sacred to Indian tribes in the area, perhaps because the high mineral content had therapeutic qualities. Photo taken on August 8, 2009.

[neilep]

Layered Hills in Arabia Terra on Mars
Credit: MSSS, JPL, NASA


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 Why are some hills on Mars so layered? The answer is still under investigation. Clearly, dark windblown sand surrounds outcropping of light sedimentary rock across the floor of crater Arabia Terra. The light rock clearly appears structured into many layers, the lowest of which is likely very old. Although the dark sand forms dunes, rippled dunes of lighter colored sand are easier to see surrounding the stepped mesas. Blown sand possibly itself eroded once-larger mesas into the layered hills. Most of the layered shelves are wide enough to drive a truck around. The above image, showing an area about 3 kilometers across, was taken in 2003 October by the now defunct Mars Global Surveyor spacecraft orbiting Mars.

[neilep]

SURF & SAND

Photographer: Konstantinos Christodoulopoulos
Summary Author: Konstantinos Christodoulopoulos; Jim Foster



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The photo above showing surf and sand in the Corinthian Gulf, near Corinth, Greece was captured on August 4, 2010. If you plan to visit the beach before summer ends (in the Northern Hemisphere), try to examine the swash zone; the part of the beach between high tide and low tide. Though this area is inhabited mostly by organisms too small to easily notice, it's teeming with life. A number of creatures, sand crabs for example, can be seen scurrying about. Like most of the inhabitants here they depend on the swashing of the waves to provide them sustenance. In addition, the swash zone is a feeding ground for numerous shore birds, and sea turtles come ashore to lay their eggs in the sand above high tide.

[neilep]

TWO SUNS ?
Photographer: Jane Shively
Summary Author: Jane Shively; Jim Foster


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The photo above looks like it could have been taken from a planet in a solar system having twin suns; though, it was snapped from a back yard in northern Ohio. Can you tell which is the real Sun and which is a fraud? Hint: Our constant companion is a little less showy. The true Sun is at left, and at right is a sundog. Sundogs or parhelia can be amazingly bright at times. They're found on either side of the Sun, at the same altitude, but 22 degrees away from it. Sundogs form when sunlight is refracted through oriented, hexagonal (plate-shaped) ice crystals in cirrus clouds. Sunlight enters one of the crystal's side faces and exits through an alternate side face -- refracted 22 degrees from the angle it entered. When the Sun is low is the sky, sundogs are at their brightest. On this day, it's likely that a combination of the Sun being dimmed by cloud cover and ice crystals having almost the same orientation, accounted for the near similar brightness of the Sun and its mocking sidekick.

[LeeE]

Nice pic - I've never actually seen a sundog and that's quite a good one.  You can just make out the red fringe on the sundog, giving it away and showing how it's related to rainbows.

[neilep]

Nice pic - I've never actually seen a sundog and that's quite a good one.  You can just make out the red fringe on the sundog, giving it away and showing how it's related to rainbows.

Thanks LeeE ...well spotted....re: the red fringe !

[neilep]

Chapel Creek at Pictured Rocks



Photographer: Rick Faber
Summary Author: Rick Faber; Jim Foster

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The photo above shows the tannin stained waters of Chapel Creek draining into the aquamarine waters of Lake Superior at Pictured Rocks National Lakeshore in Michigan's Upper Peninsula. Both the creek water and the waters of Lake Superior are fresh. Rather than randomly spilling into the lake and being immediately diluted, the stained water continued east close to the shoreline for a significant distance. Since the lake water was fairly calm it took a while, perhaps half a mile (one km) or more, before the mixing was complete. Currents perhaps contributed to the limited mixing, and additionally, a slight onshore breeze at the time the picture was snapped could have further constrained the potential for commingling. In South America, the sediment laden waters of the Rio Solimoes run side-by-side the clearer but black appearing waters of the Rio Negro for more than three and a half miles (6 km) before obvious mixing occurs.

[neilep]

Summer Storm, Lightning and Rainbow



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Photographer: Jens Hackmann;  Jen's Website
Summary Author: Jens Hackmann; Jim Foster


The photo above shows a muted double rainbow arching over a freshly cut grain crop, punctuated by intense lightning. It was snapped near Bad Mergentheim in southern Germany in the late afternoon of July 12, 2010. The camera is directed at the rainbow (antisolar point), and while the Sun has broken through in the west, the west-to-east moving thunderstorm has darkened the eastern sky and still packs a punch. Even after a seemingly innocuous thunderstorm has passed by, lightning can still pose a serious threat. It's best to stay in a protected area until you can no longer hear thunder.

[neilep]

Full Moon Over Mount Rainier
September 09, 2010





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Photographer: Sally Budack
Summary Author: Sally Budack; Jim Foster


The above photo shows the full Moon of July 24, 2010 centered directly above the ever picturesque Mount Rainier, Washington. It was taken just before sunset some 50  miles (80  km) away in Tacoma, Washington. This snow capped composite, or stratovolcano, stands 14,411 feet (4,392 m) above sea level towering above its surroundings. It is the loftiest summit in the Cascade Range. When the Moon is near the horizon, it seems to appear larger to us than when it resides higher in the sky. This is an illusion, however. It's no bigger when perched on the horizon than when overhead. What's different is that at the horizon the Moon has a point of reference, and our brain processes visual information into a spatial reference frame.

[mbtshoes2011]

These materials, icy dust particles coated with water, methanol and carbon dioxide, may help explain the origin of icy planetoids like comets. Scientists believe these comets may have endowed Earth with some of its water and many of its biogenic, life-enabling materials.

[Sliter]

Any explanation of where the tannin is coming from?  Although I doubt it does any harm I would have thought that it would be regarded as pollution (and if tannin is getting into the creek system then it's possible that more harmful substances could too).

Thanks LeeE...sorry for the delayed reply. Unfortunately no source for the tannin is indicated !..sorry.

The tannins are naturally occurring in many rivers of the Upper Pennisula of Michigan.  They come from Spruce, Cedar and Hemlock trees and from decaying leaves.  Tannins are also found in tea, and that is why the river and tea have the same color.  As a side note; one of the first industries of the area was tanning leather.  The tannins from the bark of Hemlock trees were used to tan leather in the early 1900's in nearby Munising, Michigan. 

[neilep]

The Dancing Auroras of Saturn
Credit: VIMS Team, JPL, ESA, NASA





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What drives auroras on Saturn? To help find out, scientists have sorted through hundreds of infrared images of Saturn taken by the Cassini spacecraft for other purposes, trying to find enough aurora images to correlate changes and make movies. Once made, some movies clearly show that Saturnian auroras can change not only with the angle of the Sun, but also as the planet rotates. Furthermore, some auroral changes appear related to waves in Saturn's magnetosphere likely caused by Saturn's moons. Pictured above, a false-colored image taken in 2007 shows Saturn in three bands of infrared light. The rings reflect relatively blue sunlight, while the planet itself glows in comparatively low energy red. A band of southern aurora in visible in green. Inspection of many more Saturnian images may well lead to an even better understanding of both Saturn's and Earth's auroras.

[neilep]

An Airplane in Front of the Moon
Credit & Copyright: Chris Thomas



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If you look closely at the Moon, you will see a large airplane in front of it. Well, not always. OK, hardly ever. But if you wait for days with your camera attached to a Moon tracker in a place where airplanes are known to pass, you might catch a good photograph of it. Well, if you're lucky. OK, extremely lucky. The above image was taken two weeks ago over South East Queensland, Australia using an exposure time of 1/250th of a second and, in the words of the photographer, "a nerve of steel".

[Geezer]

Wait a minute! That one looks a bit dodgy.

If there was enough light to illuminate the bottom of the plane, how come the con trails are only illuminated when they are in front of the Moon?

Also, with that amount of magnification, I would have thought the aeromobile would not be so well focused.

[RD]

There is a bright aura close to the plane in some areas: consistent with a soft mask being used (photoshop job).


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The direction the moon is lit from and the shadows on the plane are inconsistent.

[BTW shouldn't the rapidly rotating propellors have more motion blur than the wings ?]

An Airplane in Front of the Moon
Credit & Copyright: Chris Thomas
... in the words of the photographer, "a nerve of steel".

 "a brass neck" more like.  []

[imatfaal]

Just with rough numbers (perhaps Lee could give a better figure for airspeed) a plane of that size would be doing about 150-250m/s which would be 60cm to a meter in 1/250 of a second.  Even with the naked eye you can see that the plane is much stiller than that - ie the shutter speed was much higher.  Ignoring the obvious contradiction which claims it was taken at 1/250 (which throws doubt on the whole story) I can't really reconcile such a clear picture of a fast moving plane with lovely bright detail of moon

[RD]

It's supposed to be the moon in daylight, but the mare don't have the blue tint which they should have in daylight ...


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                                                                                                           http://www.flickr.com/photos/fpamplona/3715890266/

I think it's an image of the moon at night which has had the black sky replaced with dark blue to simulate a day moon, (but someone forgot to give the moon a blue tint). The NASA boffins should have spotted this ringer,