Comets' life 'seeding' evidence found

SAN DIEGO, March 28 (UPI) -- U.S. researchers say new evidence supports the idea comets bombarding Earth billions of years ago deposited the key ingredients for life to begin.

The research was presented at the annual meeting of the American Chemical Society in San Diego.

Research team leader Jennifer G. Blank of the Bay Area Environmental Research Institute at the NASA/Ames Research Center in Moffett Field, Calif., described experiments that recreated the conditions existing inside comets when they hit Earth's atmosphere at almost 25,000 miles per hour and crashed into the planet's surface, a society release reported Tuesday.

Using powerful laboratory "guns" and computer models the researchers hoped to understand how amino acids and other ingredients for the first living things appeared on Earth billions of years ago.

"Our research shows that the building blocks of life could, indeed, have remained intact despite the tremendous shock wave and other violent conditions in a comet impact," Blank said.

"Comets really would have been the ideal packages for delivering ingredients for the chemical evolution thought to have resulted in life."

Comets are composed of frozen gases, water, ice, dust and rock, described by astronomers as "dirty snowballs."

"We like the comet delivery scenario because it includes all of the ingredients for life -- amino acids, water and energy," Blank said.