Partial Ingredients For DNA And Protein Found Around Star

NASA via ScienceDaily.com ^ | 2005-12-30 | NA

[neverdem]

Partial Ingredients For DNA And Protein Found Around Star NASA's Spitzer Space Telescope has discovered some of life's most basic ingredients in the dust swirling around a young star. The ingredients - gaseous precursors to DNA and protein - were detected in the star's terrestrial planet zone, a region where rocky planets such as Earth are thought to be born.

The findings represent the first time that these gases, called acetylene and hydrogen cyanide, have been found in a terrestrial planet zone outside of our own.

"This infant system might look a lot like ours did billions of years ago, before life arose on Earth," said Fred Lahuis of Leiden Observatory in the Netherlands and the Dutch space research institute called SRON. Lahuis is lead author of a paper to be published in the Jan. 10 issue of the Astrophysical Journal Letters.

Lahuis and his colleagues spotted the organic, or carbon-containing, gases around a star called IRS 46. The star is in the Ophiuchus (pronounced OFF-ee-YOO-kuss), or "snake carrier," constellation about 375 light-years from Earth. This constellation harbors a huge cloud of gas and dust in the process of a major stellar baby boom. Like most of the young stars here and elsewhere, IRS 46 is circled by a flat disk of spinning gas and dust that might ultimately clump together to form planets.

When the astronomers probed this star's disk with Spitzer's powerful infrared spectrometer instrument, they were surprised to find the molecular "barcodes" of large amounts of acetylene and hydrogen cyanide gases, as well as carbon dioxide gas. The team observed 100 similar young stars, but only one, IRS 46, showed unambiguous signs of the organic mix.

"The star's disk was oriented in just the right way to allow us to peer into it," said Lahuis.

The Spitzer data also revealed that the organic gases are hot. So hot, in fact, that they are most likely located near the star, about the same distance away as Earth is from our sun.

"The gases are very warm, close to or somewhat above the boiling point of water on Earth," said Dr. Adwin Boogert of the California Institute of Technology, Pasadena. "These high temperatures helped to pinpoint the location of the gases in the disk."

Organic gases such as those found around IRS 46 are found in our own solar system, in the atmospheres of the giant planets and Saturn's moon Titan, and on the icy surfaces of comets. They have also been seen around massive stars by the European Space Agency's Infrared Space Observatory, though these stars are thought to be less likely than sun-like stars to form life-bearing planets.

Here on Earth, the molecules are believed to have arrived billions of years ago, possibly via comets or comet dust that rained down from the sky. Acetylene and hydrogen cyanide link up together in the presence of water to form some of the chemical units of life's most essential compounds, DNA and protein. These chemical units are several of the 20 amino acids that make up protein and one of the four chemical bases that make up DNA.

"If you add hydrogen cyanide, acetylene and water together in a test tube and give them an appropriate surface on which to be concentrated and react, you'll get a slew of organic compounds including amino acids and a DNA purine base called adenine," said Dr. Geoffrey Blake of Caltech, a co-author of the paper. "And now, we can detect these same molecules in the planet zone of a star hundreds of light-years away."

Follow-up observations with the W.M. Keck Telescope atop Mauna Kea in Hawaii confirmed the Spitzer findings and suggested the presence of a wind emerging from the inner region of IRS 46's disk. This wind will blow away debris in the disk, clearing the way for the possible formation of Earth-like planets.

The Jet Propulsion Laboratory manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at Caltech. JPL is a division of Caltech. Spitzer's infrared spectrograph was built by Cornell University, Ithaca, N.Y. Its development was led by Dr. Jim Houck of Cornell.

For graphics and more information about Spitzer, visit http://www.spitzer.caltech.edu/spitzer . For more information about NASA and agency programs on the Web, visit http://www.nasa.gov/home/ .

Editor's Note: The original news release can be found here.

This story has been adapted from a news release issued by National Aeronautics And Space Administration.

[<1/1,000,000th%]

It's becoming more obvious that the organic precursor molecules to life are created either from CME's, or from the destruction of the stars themselves when they go nova.

Fascinating.

[neverdem]

What is CME besides Continuing Medical Education?

[inquest]

I think he might be referring to Coronal Mass Ejections.

[neverdem]

Thanks for the tip. Happy New Year!

[inquest]

Happy to be of help. Happy New Year back to you.

[Theophilus]

"The gases are very warm, close to or somewhat above the boiling point of water on Earth," said Dr. Adwin Boogert of the California Institute of Technology, Pasadena. "These high temperatures helped to pinpoint the location of the gases in the disk."

This is close to or somewhat like useful information, like: someone named Chang lives in China! Thank you so much Dr Boogart!!!

[<1/1,000,000th%]

Sorry.

Inquest is correct.

Since the ionized atoms are already present in the corona and on the surface of stars, they could interact chemically once they've left the star and cooled sufficiently.

I haven't seen anyone work out any details yet.

[inquest]

Since the ionized atoms are already present in the corona and on the surface of stars, they could interact chemically once they've left the star and cooled sufficiently.

They're also present in the general solar wind. Do we know how much gets released in CME's versus in the continuous stream of solar wind?

A real interesting question, that the article really only obliquely touches on, is whether what they're looking at is really more or less what our own system would have looked like at a similar age. In other words, was the concentration of these molecules in our system at the time large enough to have registered on a spectrometer located in another star system? If the answer is yes, then it really goes to show how uncommon life in the universe likely is.

[<1/1,000,000th%]

I was focused on the more concentrated material that a star would release, but you're right. There should be some quantity of organic compounds in solar wind. I don't know if this has been measured outside of the PANH measurements. These were more just establishing the presence of PANH's.

Our solar system being relatively new in the universe, it would have been seeded with organic molecules even before our sun formed. The fact that nearly every moon, comet and rock that's been observed has organic compounds on it seems to confirm this.

I suppose you could make an argument that organic compounds could've formed soon after matter precipitated out of the aftermath of the big bang. It would've required some fusion to have occurred to produce the elements. Since the origin of galaxies and their accompanying black holes is still up for grabs, I suppose there's still room for some speculation.

[inquest]

Our solar system being relatively new in the universe, it would have been seeded with organic molecules even before our sun formed.

But we've been looking at even newer systems lately - brand new ones, in fact. Some of them, it's true, are going to be first-generation, formed directly out of primordial gas clouds. But many others are going to be second- or third-generation. Does the fact that we're just now detecting these compounds at another star mean that most stars don't have them in a large enough quantity to support life, or that this particular star in Ophiuchus has an overabundance of them for some reason? I wish the article had given some indication one way or the other.

[<1/1,000,000th%]

There are new systems, but the matter that makes them up has already been seeded with material from the first generation of stars, or whatever, nearly 12 1/2 billion years ago. At least that's the current thinking until someone comes up with a reason to change it.

The reason that these compounds are being detected now is because the technology for detecting them is relatively new and no one really thought to look. Previously thinking was that precursor molecules to life form on planets. Why would anyone look in space?

This is really a new area of research so hopefully there's a lot more news to come.

[ericthecurdog]

Bravo.

[SunkenCiv]

Note: this topic was posted 12/31/2005. Thanks neverdem.

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[SunkenCiv]

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