Study suggests comets may have delivered more water to Earth than previously thought

Recent analysis of data from the European Space Agency's Rosetta mission suggests that comets may have contributed more water to Earth than previously believed. This challenges the past view that comets were not significant sources of Earth's water. The study focused on the "rubber-ducky" comet and indicates that repeated collisions with comets and asteroids likely delivered most of Earth's water. This contrasts with earlier theories that emphasized geological processes as the primary source. Scientists noted that Earth's deuterium-to-hydrogen ratio aligns with that of certain asteroids and some comets, supporting the idea of cometary contributions. This research revives interest in the role of comets in Earth's water history.