[LINK] "More Evidence That Comets May Have Brought Life to Earth"

[rfmcdonald]

Universe Today's Nancy Atkinson presents evidence comets may have contributed to life on Earth, not by importing it but rather by making the precursor chemical compounds to life.

The idea of panspermia — that life on Earth originated from comets or asteroids bombarding our planet — is not new. But new research may have given the theory a boost. Scientists from Japan say their experiments show that early comet impacts could have caused amino acids to change into peptides, becoming the first building blocks of life. Not only would this help explain the genesis of life on Earth, but it could also have implications for life on other worlds.

Dr. Haruna Sugahara, from the Japan Agency for Marine-Earth Science and Technology in Yokahama, and Dr. Koichi Mimura, from Nagoya University said they conducted “shock experiments on frozen mixtures of amino acid, water ice and silicate (forsterite) at cryogenic condition (77 K),” according to their paper. “In the experiments, the frozen amino acid mixture was sealed into a capsule … a vertical propellant gun was used to [simulate] impact shock.”

They analyzed the post-impact mixture with gas chromatography, and found that some of the amino acids had joined into short peptides of up to 3 units long (tripeptides).

Based on the experimental data, the researchers were able to estimate that the amount of peptides produced would be around the same as had been thought to be produced by normal terrestrial processes (such as lighting storms or hydration and dehydration cycles).