Computer Simulations Suggest Building Blocks of Life Didn't Arrive on Prehistoric Comets

CNN reports: The popular theory that comets were crucial in kick-starting life on Earth billions of years ago may not hold up, according to new computer simulations that counter decades of scientific thinking. The finding suggests the fragile organic molecules supposedly carried by the icy objects would have been destroyed on impact, upending an established origin of life theory that dates back to at least 1961 [with earlier versions postulated in 1908]... Early in its history — over 4 billion years ago — Earth may have experienced a period of heavy bombardment from more than 100,000 comets larger than 100 meters (328 feet), according to the new study, published Wednesday in the journal Scientific Reports. Those impacts, however, were mostly too heavy for life-starting molecules to withstand. The team used the latest models of comet formation and evolution to simulate this early planetary period 100,000 times. "Given what we know about surface environments on the early Earth, on average, our simulations found that there were no successful impacts," said lead study author Richard Anslow, who conducted the research while completing his doctorate at the Institute of Astronomy of the U