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 ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. A composite image comparing the relative sizes of our solar system's known dwarf planets, ...

On July 14, 2015, NASA's New Horizons spacecraft arrived at Pluto for the first time. The craft flew within 7,700 miles of the planet and is sending back reams of data and the highest resolution ...

A composite image showing the five dwarf planets recognized by the International Astronomical Union, plus the newly discovered trans-Neptunian object 2017 OF201. The TNO is potentially large enough to ...

A recent research paper suggests that a planet may exist far beyond Neptune — less than 20 years after the previous ninth planet, Pluto, was demoted. That research paper, accepted last month for ...

In 2006, updated research led to Pluto being controversially demoted to dwarf planet status by the International Astronomical Union. The reasoning was that Pluto's location in the far-flung ...

Once the quirky underdog of our solar system, Pluto held planetary status until 2006, when it got a cosmic demotion that still stings space fans. Discovered in 1930, Pluto was the ninth planet for ...

Pluto sits far out in the Solar System, small and dim, moving at a pace that barely fits human timelines. It was found in ...

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 system ...