The Eternal Life of Stardust

[Waspie_Dwarf]

The Eternal Life of Stardust Portrayed in New NASA Image

A new image from NASA's Spitzer Space Telescope is helping astronomers understand how stardust is recycled in galaxies.

The cosmic portrait shows the Large Magellanic Cloud, a nearby dwarf galaxy named after Ferdinand Magellan, the seafaring explorer who observed the murky object at night during his fleet's historic journey around Earth. Now, nearly 500 years after Magellan's voyage, astronomers are studying Spitzer's view of this galaxy to learn more about the circular journey of stardust, from stars to space and back again.


Image above: Spitzer's infrared view of the Large Magellanic Cloud. The blue color, seen most prominently in the central bar, represents starlight from older stars. The chaotic, bright regions outside this bar are filled with hot, massive stars buried in thick blankets of dust. The red color around these bright regions is from dust heated by stars, while the red dots scattered throughout the picture are either dusty, old stars or more distant galaxies. The greenish clouds contain cooler interstellar gas and molecular-sized dust grains illuminated by ambient starlight.
Image credit: NASA/JPL-Caltech/STScI
+ Browse version of image

"The Large Magellanic Cloud is like an open book," said Dr. Margaret Meixner of the Space Telescope Science Institute, Baltimore, Md. "We can see the entire lifecycle of matter in a galaxy in this one snapshot." Meixner is lead author of a paper on the findings to appear in the November 2006 issue of the Astronomical Journal.

The vibrant false-color image, a mosaic of approximately 300,000 individual frames, shows a central blue sea of stars amidst lots of colorful, choppy waves of dust. It can be viewed at: http://www.spitzer.caltech.edu/Media/releases/ssc2006-17/ssc2006-17b.shtml.

Space dust is important for making stars, planets and even people. The tiny particles -- flecks of minerals, ices and carbon-rich molecules -- are everywhere in the universe. Developing stars and solar systems are constantly consuming dust, while older stars shed dust back into space, where it will one day provide the ingredients for new generations of stars.

Spitzer, an infrared observatory orbiting the sun, is extremely sensitive to the infrared glow of dust that arises when stars heat it up. The observatory's unprecedented view of the Large Magellanic Cloud offers a unique look at three stops on the eternal ride of dust through a galaxy: in collapsing envelopes around young stars; scattered about in the space between stars; and in expelled shells of material from old stars.

"The Spitzer observations of the Large Magellanic Cloud are giving us the most detailed look yet at how this feedback process works in an entire galaxy," said Meixner. "We can quantify how much dust is being consumed and ejected by stars."

In addition to dust, Spitzer's view reveals nearly one million never-before-seen objects, most of which are stars in the Large Magellanic Cloud. The hidden stars, both young and old, are embedded in layers of dust that block visible starlight but shine in infrared.

"We can now see the populations of old stars and stars that are currently forming," said co-author Dr. Karl Gordon of the University of Arizona, Tucson.

The Large Magellanic Cloud is one of a handful of dwarf galaxies that orbit our own Milky Way. It is located near the southern constellation Dorado, about 160,000 light-years from Earth. About one-third of the whole galaxy can be seen in the Spitzer image.

Astronomers believe that approximately six billion years ago, not long before our solar system formed, this dwarf galaxy was shaken up via a close encounter with the Milky Way. The resulting chaos triggered bursts of massive star formation similar to what is thought to occur in more primitive galaxies billions of light-years away. This and other distant-galaxy traits, such as an irregular shape and low abundance of metals, make the Large Magellanic Cloud the perfect nearby target for studying the faraway universe.

This research is part of a Spitzer Legacy program called Surveying the Agents of a Galaxy's Evolution, also known as Sage. The international Sage team includes more than 50 astronomers spread over the globe from Japan to the United States. The main data centers are located at: the Space Telescope Science Institute, Baltimore, Md., led by Meixner; University of Arizona, Tucson, led by Gordon; and University of Wisconsin, Madison, led by Dr. Barbara Whitney.

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 at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA. Spitzer's infrared array camera and multiband imaging photometer captured the new image. The camera was built by NASA's Goddard Space Flight Center, Greenbelt, Md. Its principal investigator is Dr. Giovanni Fazio of the Harvard-Smithsonian Center for Astrophysics. The photometer was built by Ball Aerospace Corporation, Boulder, Colo.; the University of Arizona; and Boeing North American, Canoga Park, Calif. Its principal investigator is Dr. George Rieke of the University of Arizona, Tucson.

For more information about Spitzer visit www.spitzer.caltech.edu/spitzer.

Media contact: Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.

2006-103

Source: NASA - Exploring The Universe - Stars and Galaxies

[glenndo4000]

wow...nice pic

[ROGER]

Everything on our planet is made up of Star Dust , including the complex elements that make up the Human Body!

And a Perfectly Beautiful example of Star Dust is pictured on the LEFT!

I wish I was smart rather than so darn Good Looking!

[crystal sage]

http://web99.arc.nasa.gov/~astrochm/vesicle.html

"We started this work motivated to find the types of compounds that might be in comets, icy planets and moons, providing guidance for future NASA missions," space scientist and team leader Lou Allamandola said. "Sure, we expected that ultraviolet radiation would make a few molecules that might have some biological interest, but nothing major. Instead, we found that this process transforms some of the simple chemicals that are very common in space into larger molecules which behave in far more complex ways. Ways which many people think are critical for the origin of life, the point in our history when chemistry became biology," he continued.

"Instead of finding a handful of molecules only slightly more complicated than the starting compounds, hundreds of new compounds are produced in every mixed ice we have studied," space scientist Scott Sandford said. He continued, "We are finding that the types of compounds produced in these ices are strikingly similar to many of those brought to Earth today by infalling meteorites and their smaller cousins, the interplanetary dust particles. Every year more than a hundred tons of extraterrestrial stuff falls on the Earth, and much of it is in the form of organic material. In the early life of our solar system, before the debris from its formation was fully cleared away, these materials were deposited on the Earth in far greater quantities than we see today. Thus, much of the organic material found on the Earth in its earliest years probably had an interstellar heritage."

"A number of years ago I found that some of the extraterrestrial organic compounds brought to Earth in the Murchison meteorite could form membranous vesicles when they interacted with water," said team member Dave Deamer, Professor of Chemistry at the University of California at Santa Cruz. Vesicles are microscopic, hollow droplets with sizes, shapes and structures similar to those of certain living cells. "All life today is cellular, and cells are defined by membranes that separate the cytoplasm from the outside world. When life began, at some point it became compartmented in the form of cells. But where did the first cell membranes come from? Maybe they were composed of molecules similar to those we discovered earlier in meteorites," Deamer continued. "When I learned of the ice experiments at NASA Ames, I went to the Astrochemistry Lab intending to find out what would happen when their complex organic mixtures were allowed to interact with water. To our surprise and delight we found that vesicular structures formed that looked very much like those we saw in the Murchison material."

"We now know that of the hundreds of new compounds we make in these interstellar ice simulation experiments, many have properties relevant to the origin of life," said biochemist Jason Dworkin. "Upon the addition of liquid water to the organics produced during ice irradiation, some of these new compounds, with no outside help, organize themselves into tiny vesicles with complicated structures. Other new compounds formed are so much more complex than what we started with that they glow when exposed to UV light. Not only that, but these molecules, which can convert energy from the ultraviolet light to the visible range, become part of the self-formed vesicles," continued Dworkin. "Molecules that do these things are thought to be extremely important for the origin of life. Membrane structures are necessary to separate and protect the chemistry involved in the life process from that in the outside environment, and all known biology uses membranes to capture and generate cellular energy," Dworkin said.

[crystal sage]

'Red Rain of Kerala' is it stardust???

it seems so...

http://www.centauri-dreams.org/?feed=rss2&p=667

Edited October 3, 2006 by crystal sage

[RollingThunder06]

Never really thought about stardust. The picture makes it even more mysterious and beautiful.