Earth’s deep interior may hold water equal to today’s oceans, challenging long-held views of how the planet became habitable.

Our planet is unique for its ability to sustain abundant life. From studies of the rock record, scientists believe life had already emerged on Earth at least 3.5 billion years ago and probably much ...

Planetary scientists analyzing oxygen isotopes in lunar soil from the Apollo mission sites conclude that meteorite bombardment over 4 billion years could only have delivered a tiny fraction of Earth’s ...