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

The discovery of 2017 OF201 is significant, as it challenges the hypothesis of Planet Nine, a hypothetical planet thought to ...

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

Scientists believe such an extreme orbit means the object was pushed and pulled by the gravity of giant planets like Jupiter ...

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 ...

At the very edge of our solar system, beyond the grasp of Neptune and even past the icy sprawl of Pluto’s domain, a new ...

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

The presence of another planet in the solar system could explain the odd movements of some of the bodies in the Kuiper Belt.

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

Last time that happened, Pluto was kicked out of the club, but the new proposed definition is designed to be more inclusive. Exactly what a planet is ... trying to achieve. Beyond this minimum ...