University of Cambridge study challenges theory of life arriving via comets

A new study led by the University of Cambridge suggests that comets may not have been the primary delivery mechanism for the chemical building blocks of life on Earth. While comets contain organic molecules like hydrogen cyanide (HCN) essential for prebiotic chemistry, researchers found that the physical process of delivery is highly problematic.

Through 100,000 computer simulations, the investigation analyzed the impact of comet entry speeds and atmospheric angles. The results indicated that in 54% of the scenarios, the molecules failed to reach the surface in concentrations relevant to life, either due to being destroyed by heat during atmospheric entry or being diluted upon impact with oceans. Dr. Richard Anslow described the possibility of these molecules successfully delivering life-starting ingredients as a “one in a million” coincidence.