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 consistent with a large, distant planet.

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

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

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

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

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

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

But do other planets have seasonal patterns, too? Indeed, other planets, dwarf planets and moons in our solar system do have seasonal cycles — and they can look wildly different from the ones we ...