Learn how a possible ninth planet, the theoretical Planet X, could have acquired its wide orbit in the outer Solar System - a ...

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system.

There’s a new object in the distant reaches of our solar system, and it might just offer clues to a long-standing cosmic ...

A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

Astronomers have announced the discovery of a new dwarf planet in our solar system, named 2017 OF201. Located far beyond ...

A small team led by Sihao Cheng, Martin A. and Helen Chooljian Member in the Institute for Advanced Study's School of Natural ...

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be ...

The unusual orbit of a possible dwarf planet, known as 2017 OF201, makes it less likely that our solar system contains a ...

The International Astronomical Union’s Minor Planet Center, which catalogs new moons and other small bodies in the solar ...

In the cold, distant reaches of the Solar System, far beyond Pluto, astronomers have just identified what could be a new ...

Astronomers have discovered a mysterious dwarf planet, 2017 OF201, far beyond Pluto. This discovery challenges existing ...

Learn about the recently discovered trans-Neptunian object that may eventually join Pluto as a dwarf planet, found at the edge of our solar system.