Uranus and Neptune will also be on the scene, too dim to see with the naked eye. Look to the western horizon at sunset on Feb. 20 to witness an incredible sight, as three planets shine below the ...

It would be understandable if you stopped thinking as much about Pluto after it was “demoted” from being considered one of the nine planets sharing the Earth’s solar system to being classified as a ...

NASA’sNew Horizons spacecraft has delivered extraordinary video footage showing towering ice mountains on Pluto’s moon Nix. These ice peaks, some rising as high as 11,000 feet, are made of pure water ...

Pluto's discovery by Clyde Tombaugh, key political changes in Scandinavia and America, plus cultural and scientific milestones.

Astronomers have uncovered a planetary system that challenges conventional theories of planet formation. The system likely includes a rocky planet that formed beyond the orbits of its gaseous ...

Since the 1990s, scientists have discovered approximately 6,100 planets outside our solar system, called exoplanets.

Four planets observed orbiting a red dwarf star; rocky outermost planet challenges formation theory, says scientists.