Everyone's favorite dwarf planet, Pluto, was discovered just 95 years ago. Here's the story of how the once-ninth planet was ...

Although Pluto's orbit was more elongated than the other planets ... (The object is now called Eris.) Over a thousand objects are now known to orbit the Sun beyond Neptune, and once again ...

The International Astronomical Union reclassified Pluto as a dwarf planet because it does not clear its orbit of other debris. Pluto was the little planet that could — until it couldn’t.

Gonggong is a dwarf planet and a member of the scattered disc beyond Neptune. As of 2019, its distance from the Sun is 88 AU, and it is the sixth-farthest known Solar System object.

Pluto, Eris, Ceres, Makemake ... Those guys are going to spend most of their time at the outer edge of their orbit, so they're hard to see," Brown said. "There might be a factor of ~5 more ...

Pluto and Charon orbit a shared center of mass, much like figure skaters spinning together, a result of their unique collision process. The collision deposited internal heat into both bodies ...