The new finding is challenging established theories of how planets come to be.
Life needs more than water alone. Recent discoveries suggest that plate tectonics has played a critical role in nourishing life on Earth. The findings carry major consequences for the search for life elsewhere in the universe.
A series of fossil finds suggests that life on Earth started earlier than anyone thought, calling into question a widely held theory of the solar system’s beginnings.
Textbooks say that the moon was formed after a Mars-size mass smashed the young Earth. But new evidence has cast doubt on that story, leaving researchers to dream up new ways to get a giant rock into orbit.