Updated

Computer simulations suggest comets carrying a key precursor molecule for many of life's building blocks would rarely have reached Earth's surface intact, Smithsonian Magazine reported on November 12, 2026. Even when they did, only specific landing conditions would have allowed the molecule to drive biologically relevant reactions. The findings challenge the longstanding theory that comets brought the ingredients for life to Earth, and they point to other possible origins for the chemistry that led to life.