What's up in
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.
Geochemical signals from deep inside Earth are beginning to shed light on the planet’s first 50 million years, a formative period long viewed as inaccessible to science.