Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a frequent visitor. Located beyond Neptune, its extreme orbit ...

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. In 2006, the International ...

These icy bodies orbit the sun just like the major planets, yet they follow their own rules, often traveling along elongated ...

The heart's brightness arises from sunlight reflection, while red patches, formed by tholins, showcase Pluto's atmospheric ...

Pluto has long been one of the most debated celestial bodies in our solar system. Once classified as the ninth planet, it was redefined in 2006 as a dwarf planet, a decision that still sparks ...

(Correction: An earlier version of this story misstated how far Pluto is from the sun. The correct number is 3.7 billion miles.) What was discovered in Flagstaff, Arizona, and killed off in Prague? If ...

Pluto, discovered in 1930, was once considered the ninth planet in our solar system. In 2006, the International Astronomical Union reclassified Pluto as a dwarf planet because it doesn't meet all the ...

Astronomers searching for the faintest glimmers of light beyond distant Pluto say they’ve discovered a new dwarf planet – and that this planetoid’s movements hint that an invisible giant planet ...