The rusty world is full of mysteries—and some of the solar system's most extreme geology. Learn more about Earth's smaller, colder neighbor.

University of Bristol astrophysicists are helping shed new light on an Earth-sized exoplanet 40 light years away where liquid ...

Evidence is mounting that a world the size of Neptune could be orbiting a giant planet far, far away.

The planet Mercury will soon be at its best for skywatchers on Earth. These views, based on data from NASA's MESSENGER spacecraft, show the planet's surface in stunning detail. We have just ...

Discover interesting facts about how Earth formed, what it's made of and more.

Discover interesting facts about Saturn, its rings and whether it could contain extraterrestrial life.

Reference Article: Facts about Eris, the first dwarf planet discovered. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Eris was one of the ...

Mercury is putting on a show for skywatchers in the evening sky after sunset. But how well do you know the planet Mercury? Here's some Mercury trivia to ponder while planet gazing.

American astronomers say they have found strong evidence that a ninth planet might exist in our solar system. Here are nine things we know about 'Planet Nine'.