Scientists say they were "truly astonished" by a discovery that calls into question a longstanding story of how Earth came to be. According to a new study, Earth formed almost entirely from material in the inner Solar System, rather than incorporating large amounts of water-rich material from beyond Jupiter.
The study challenges the conventional view that water and other volatile compounds were delivered to Earth later by icy bodies from the outer Solar System. If the new interpretation is correct, water may have been present much closer to the young Sun than scientists had thought.
Because this is a single source, the findings are presented as one team's proposal rather than a settled conclusion. Still, the results could reshape the way researchers think about planet formation and the origins of Earth's water.