The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

The new exoplanet, Enaiposha, also known as GJ 1214 b has never been seen before and is now officially being called a "Super-Venus." ...

Continent-size islands deep inside Earth's mantle could be more than a billion years old, a new study finds.

A suspected planet that appears well-suited to life has had its existence confirmed – and it’s very much in our neighborhood, ...

Astronomers have found two planets around two separate stars that are succumbing to their stars' intense heat.

“Pluto and Charon are different — they ... both a large fraction of the size of the main body they orbit, which is unlike other smaller moons orbiting planets throughout our solar system.

"Pluto and Charon are different—they're ... complex bodies despite their small size and cold temperatures,” NASA said. Pluto may not be a full-fledged planet, but it continues to fuel ...