The basic stuff of life had better than a snowball's chance of taking hold on Earth, accor-ding to defense scientists who spent weeks smacking simulated comets into this rocky planet. They found that dusty iceballs of ordinary size, sweeping up amino acids in the outer solar system, could skid into ancient Earth at missile warhead speed -- and leave shallow lakes teeming with the precursors of living organisms. Carnegie Mellon chemical engineering student Benjamin Karlow and colleagues at Lawrence Livermore National Laboratory suspect comet splash-downs could have dumpedmillions of tons of intact organ- ic chemicals on Earth and perhaps shocked them a step closer to forming proteins. If they're right, comets could be 10 times more likely as a potential explanation for life here than, say, lightning striking a primordial soup or bacteria born in a deep ocean hot vent. "We think there's a place in there where a good amount accretes and survives," said Karlow.

It's the latest support for a century-old theory known as "panspermia," which is Greek for "seeds everywhere." In the 1970s, British astronomers Fred Hoyle and Chandra Wickramsinghe popularized the idea in its classic form: The first Earthlings were germs that sprinkled down from outer space. Mainstream scientists figured the two had gone off the deep beyond. "There you had these living entities undefined, wafting through space, and wherever they felt it was hospitable, they set up shop," said Rocco Mancinelli, an astrobiologist at the Mountain View-based SETI Institute.


View: Full Article | Source: The Argus Online