leonids_biology_001115_MB_ Data from instruments flown on airplanes during last year's Leonid meteor shower show that the seeds of life, long suspected to exist in comet dust, could have survived a fiery passage from space to Earth's ancient atmosphere.
A range of findings, reported by an international team of NASA-led scientists, provide support for
panspermia, which holds that life on Earth did not spring up spontaneously out of some primordial soup, but was instead seeded from space.[uplink]
"Findings to date indicate that the chemical precursors to life -- found in comet dust -- may well have survived a plunge into early Earth's atmosphere," said astronomer Peter Jenniskens of the Ames Research Center and the
SETI Institute. The studies were published in a November 14 special edition of the Netherlands journal Earth, Moon and Planets.
Sowing the seeds
The idea that the seeds of life, or life itself, constantly fall from space is the central idea of panspermia. Not only did life on Earth begin this way, the concept holds, but the genetic pool is constantly modified, even today.
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Many mainstream scientists have long derided panspermia. But the view has shifted noticeably in recent months.
Other researchers have shown that meteors both small and large do not heat up as much as previously thought, allowing the possibility that dormant life could arrive on an incoming space rock or, just possibly, embedded in the dust grain of a comet.
Jenniskens and others said all this work at least supports the notion that life's recipe -- in the form of organic molecules -- can survive the trip into the atmosphere.
Chandra Wickramasinghe, a leading proponent of panspermia, cheered the newest work.
"I think the results reported by NASA are clear proof that bacterial particles could survive, hence vindicating panspermia," Wickramasinghe said. He and astronomer Sir Fred Hoyle have, since the 1970s, argued that organic particles of bacterial sizes survive entry through the atmosphere.
"However, there is still a tendency to interpret results like this as merely showing that organics, rather than life, are being added to the Earth, but the trend is surely moving towards panspermia," Wickramasinghe told SPACE.com.
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