Worlds will align for a "planetary parade" in January, with four bright and easily visible to the naked eye. But an even ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

A powerful new tool comes online this year that could help astronomers locate the mysterious planet hiding somewhere beyond ...

For much of January and February, you have the chance to see six planets in our solar system after dark, although two — Uranus and Neptune — will be hard to see without a telescope or high-powered ...

Plate tectonics give Earth its mountains, earthquakes, continental drift and maybe even helped give rise to life itself. But ...