Earth is home to some truly bizarre and breathtaking landscapes — here are 20 that look straight out of an alien world.

Mars, Venus, Jupiter and Saturn should be visible to the naked eye, but get a telescope and you can spot Neptune and Uranus.

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

A super-Earth planet that dips in and out of its star's habitable zone has been discovered just 19.7 light-years away.

"This agreement represents a significant milestone for Planet; it is our largest contract to date and is a major step forward ...

Mars' southern hemisphere absorbs a lot of the sun's energy during the Red Planet's spring, and that may be causing Mars' ...

A U.S. scientist searching for a civilization across 7 Earth clones circling the red dwarf star TRAPPIST-1 says its own alien ...

Research on hidden structures deep within Earth’s mantle challenges theories about our planet’s middle layer and could ...

Researchers say there’s a 1.3 percent chance that the space rock 2024 YR4 could strike our planet — but not until December ...

Peculiar bursts of energy called chorus waves have been detected in deep space far from our planet, suggesting they could ...

Astronomers discovered supersonic winds on a giant gas planet located over 500 light-years from Earth. In a study released ...

Exciting February sky events include Venus at its brightest and closest to Earth, the moon occulting the Pleiades, and a parade of planets in the post-sunset sky.