Cambridge researchers find comet impacts unlikely to seed life
Cambridge researchers said their latest computer models show that the intense heat and pressure of high-speed comet impacts would destroy key organic molecules, rendering the delivery of life's building blocks by comets to early Earth highly improbable. The team had earlier argued that comet-borne prebiotic chemicals such as hydrogen cyanide would be unlikely to survive impact, noting that simulations of 100,000 impacts suggested delivery was extremely rare and that Mars might have offered more favorable conditions. These findings echo earlier computer-simulation studies that questioned the long-standing hypothesis that comets supplied the organic precursors for life on Earth.