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

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 ...

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

Researchers say they found a curious dot on infrared images taken 23 years apart that seems to be moving in a manner consistent with a large, distant planet.

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

Their new study offers ... Denton explained, “Pluto and Charon are smaller, colder, and primarily made of rock and ice. When we accounted for their material strength, we discovered something ...

NEW YORK (AP) — A newly discovered green comet tracked by telescopes has likely broken apart as it swung by the sun, dashing hopes of a naked-eye spectacle.