This artist’s concept depicts one of the solar system’s inner planets slamming into Earth after being nudged on a collision course by a passing star. Such a world-shattering cataclysm is extremely ...

Illustration comparing the planets of the Solar System and the Sun on the same scale. The planets are shown to scale relative to each other but their distances are not. From left to right the bodies ...

The formation of our solar system from a singular nebula raises an intriguing question: why did each planet develop with a ...

A long-lost planet that helped create the Moon may have formed much closer to the Sun than scientists once thought, according to new research. Scientists have discovered that Theia, the ancient planet ...

Roughly four and a half billion years ago the planet Theia slammed into Earth, destroying Theia, melting large fractions of Earth’s mantle and ejecting a huge debris disk that later formed the moon.

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course. When ...