When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...

The fact that our solar system has eight planets (unless you’re a Pluto apologist) is one of the first things we learn in our educational journey (anyone remember the “Blue’s Clues” planet song?). But ...

Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system was touted more than a century ago. But ...

Looks like our solar system isn't the only one out there with eight planets circling around a single star. Scientists used Google machine learning to teach computers how to identify planets in the ...

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

All of our solar system’s planets are lining up to parade through the night sky at once. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known as a ...

PASADENA, Calif.–The International Astronomical Union (IAU) today downgraded the status of Pluto to that of a “dwarf planet,” a designation that will also be applied to the spherical body discovered ...

The Sun is orbited by eight planets, at least five dwarf planets, tens of thousands of asteroids, and around three trillion comets and icy bodies. Although not all objects of the solar system are as ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...