Sotheby's is putting some rare items up for auction, including what it calls the largest piece of Mars ever found on Earth.

NASA's Voyager 2 spacecraft made its closest approach to Jupiter. It came within 354,000 miles (570,000 kilometers) of the ...

Our Solar System is home to eight extraordinary planets, each with its own unique features, mysteries, and beauty. This cosmic journey takes you from the Sun-scorched surface of Mercury to the icy ...