Pluto is no longer considered a planet because it doesn't meet all the criteria set by the International Astronomical Union.

Legendary actor William Shatner wants President Trump to restore Pluto to greatness as scientists claim to have found a “new” ...

The International Astronomical Union, which reclassified Pluto as a dwarf planet in 2006, is the arbiter of such ...

Billions of years ago, in the frozen edges of the solar system, a violent impact shaped one of space’s oddest pairs. Instead ...

Stars that pass close to the solar system could pull planets out of alignment, sending them hurtling into the sun or out into ...

Researchers say they found a curious dot on infrared images taken 23 years apart that seems to be moving in a manner ...

Instead of a typical planet-moon setup, Pluto and Charon became a binary system. They circle a shared point in space, locked in a delicate, endless orbit. Their strange gravitational dance has ...