For three-quarters of a century, schoolkids learned that our solar system has nine planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. But things changed five years ago.

For the dwarf planet candidate, one trip around the sun takes over 24,000 years. Its orbit challenges a proposed path for a hypothetical Planet Nine.

Researchers found the object named 2017 OF201 while searching for "Planet Nine" - a hypothetical planet thought to exist ...

A newly found object may set a new record for the most distant dwarf planet in the solar system. The object, called V774104, lies about nine and a half billion miles from the sun, or two to three ...

In the cold, distant reaches of the Solar System, far beyond Pluto, astronomers have just identified what could be a new dwarf planet. It's called 2017 OF 201, a rock that appears to be some 700 ...

So many unexplored secrets still lie at the outskirts of our solar system, where a potential candidate for a new dwarf planet lies. Although space beyond Neptune was thought to be mostly devoid of ...

Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar ...

A large asteroid could be reclassified as a dwarf planet – which could make it the smallest in the solar system – after new research revealed its shape, astronomers said on Monday. Nestled in ...

[Our Solar System: A Photo Tour of the Planets] You may like Scientists found a possible new dwarf planet — it could spell bad news for Planet 9 fans Solar system guide: Discover the order of ...

Although hundreds, or perhaps thousands, more solar system bodies may eventually join the list, the IAU officially recognizes just five dwarf planets at the moment. Here's a brief tour of all five ...