For decades, our solar system was thought to have nine planets, with Pluto considered the smallest and farthest. But in 2006, ...

a yellow dwarf star that contains 99.8% of the solar system's mass. Everything else — from the eight major planets to dwarf planets, comets, asteroids, and icy objects — revolves around it.

But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might still be nine if some astronomers are correct about an as-yet ...

Astronomers find evidence of a possible ninth planet beyond Neptune, reigniting the debate about the formation of the Solar ...

As a result of the International Astronomical Union’s 2006 demotion of Pluto from planet to dwarf planet, our solar system ...

The planets of the solar system were lined up in the sky Wednesday ... to happen at least every couple of years. In fact, the eight-planet alignment last happened in June. In order to see the ...

For the dwarf planet candidate, one trip around the sun takes over 24,000 years. Its orbit challenges a proposed path for a hypothetical Planet Nine.

There are eight planets in your Snapchat Solar System. It ranks all planets based on how close you are to your friends. The app assigns Venus to your second-best friend and goes to Neptune ...

A recent study found that Jupiter was once twice the size that it is now, making it big enough to swallow up 2,000 Earths.

The eight planets in our solar system orbit the sun in roughly the same plane because they all originally formed from the same disc of debris around the sun. The line the sun traces across the ...

The eight planets in our solar system orbit the sun in roughly the same plane, because they all originally formed from the same disc of debris around the sun. The line the sun traces across the ...