The potential discovery of a large planet beyond Neptune’s orbit could change everything we know about the Solar System.

The newcomer replacing Pluto presently goes by “Planet Nine.” If and when it finally shows up, it will get the honor of a ...

There are eight official planets (sorry, Pluto) in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and ...

Sky gazers will get a peek at what has been called a "parade of planets," where this time around, up to seven planets may ...

The BepiColombo spacecraft has sent back some incredibly detailed images of Mercury’s north pole. The snapshots were ...

A very rare treat is about to grace Earth's night skies.

NASA's Director of Planetary Science, Jim Green, discusses the Jan. 20 2016 Astronomical Journal science paper that points to ...

Pluto likely acquired large moon Charon in a “kiss and capture” collision billions of years ago. It may have created a subsurface ocean on the icy dwarf planet.

Enigmatic planet Mercury posed for some closeups when the BepiColombo mission flew by. Craters, bright regions and volcanic ...

Accessible to anyone the world over, witnessing the majesty of the solar system, including the Milky Way, and its billions of ...

The close-up images reveal craters, the floors of which are in permanent shadow, and vast sunlit northern plains.

Some stargazers are calling it a planetary parade: Every other planet in our solar system can be seen in the sky tonight.