Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, ...

Researchers say they found a curious dot on infrared images taken 23 years apart that seems to be moving in a manner ...

Discovered in 1930, Pluto was long considered our Solar System's ninth planet, but was unseated in 2006 after the discovery ...

Earth has four seasons, but do other planets in our solar system also have hot summer days and cold winter nights?

Pluto was discovered in 1930 in Arizona, but in 2006 scientists decided to cut Pluto from the planetary line up. Here is why ...

Discovered in 1930, Pluto was long considered our Solar System's ninth planet, but was unseated in 2006 after the discovery ...

A new look through decades-old data has unveiled some of the most compelling evidence yet of a hidden ninth planet in the far ...

Astronomers may have found a candidate for Planet Nine. This planet is beyond Neptune. The finding could be the first ...

The solar system is our cosmic neighborhood ... Everything else — from the eight major planets to dwarf planets, comets, asteroids, and icy objects — revolves around it.

The solar system consists of our star, the sun, and everything bound to it by gravity: the planets Mercury, Venus, Earth, ...