Recent scientific observations have sparked a flurry of questions and theories about the Red Planet. Anomalies detected over Mars’s North Pole and peculiar burrowing features on its surface have ...

The big picture: Theia is a hypothetical ancient planet that orbited the Sun during the formation of the solar system. According to the giant-impact hypothesis, this protoplanet collided with Earth ...

Root explores how Earth’s gravity field is constantly changing and what these variations reveal about our planet ...