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

Stargazers will be treated to a rare seven-planet alignment in February. This is what scientists hope to learn.

Alignments of five or more planets are rare—there will be two more featuring five or more planets this year, but after that ...

Jupiter's Great Red Spot storm, which usually appears dark-red, can be seen shining a lurid blue color in an ultraviolet ...

Venus and Saturn will be in conjunction this weekend, appearing side by side in the night sky during January's post-sunset ...

Although Jupiter and Mars have been dominating the eastern sky, there's more here to view than just planets. Already 50° high ...

Research and development is underway to create robots that can hunt for signs of life in the vast oceans that exist under the ...