Earlier this year, the work of Nir Goldman and colleagues was noted (here). Using sophisticated computer modeling tools, it was concluded that cometary impacts could generate C-N bonded oligomers that subsequently break apart to form a glycine-containing complex. This research has now been published in Nature Chemistry, resulting in a new flurry of discussion about the shock synthesis of life.
It is known from Stanley Miller’s experiments that amino acids can be synthesized in a reducing atmosphere. However, the evidence for such an atmosphere has become less convincing with time – and even a neutral atmosphere means the Miller route for generating amino acids is unproductive. Cometary impacts, however, can make this point irrelevant, as is explained by John Timmer here.
“One of the problems facing origin-of-life research is that building complex organic chemicals requires a reducing environment, but the early Earth’s atmosphere is now thought to have been weakly oxidizing. None of this matters as the comet hits. A typical shockwave quickly reaches conditions where the simple compounds break down, liberating hydrogen ions. These create local reducing environments no matter what the atmosphere looks like.”
For more, go here.