|
 |
 advertisement
| |
|
|
|
|
|
Seeds of Life on Earth Could Look More Like Us
By Jeff Kanipe
Special to space.com
posted: 12:23 pm ET
13 January 2000
|
Searching for the Origins of Life on Earth among the StarsThe seeds of life on Earth could have been carbon-based molecules from stars, rather than simple inorganic molecules lacking that life-linked element, a team of astronomers said Wednesday. "Life did not have to begin with simple inorganic molecules," said Sun Kwok, of the University of Calgary, referring to a previously accepted theory from the 1950s that inorganic molecules of hydrogen, methane, and ammonia in a primordial muck was energized by lightning to become the building blocks for more complex organic molecules. Using data gathered by the European Space Agency's Infrared Space Observatory, Kwok and astronomers Kevin Volk of the University of Calgary and Bruce Hrivnak of Valparaiso University found the signatures of organic molecules in the outermost atmospheres of a class of extremely old stars called carbon stars. As their name implies, carbon stars have an overabundance of carbon relative to oxygen. This and their low temperatures allow for the formation of complex carbon compounds in their very low-dense outer atmosphere. Although scientists don't understand exactly how chemical reactions occur in such a rarefied environment, Kwok said the team's research shows that molecules can synthesize within a period of only several thousand years. "There is no doubt that such complex molecules exist, and the stars are able to make them with no difficulty," said Kwok. When these stars die, their atmospheres disperse into the interstellar medium. It is possible, though not very likely, said Kwok, that some of the organic molecules could traverse space and end up on planets like Earth. If so, "life would have had an easier time developing on Earth," he said. Such a mechanism, if robust enough, could mean that life is common in the universe, he said.
|
|
|
|
|
