While Mercury is the innermost planet in the Solar System, on average it spends more time closer to Earth than Venus does.

A telescope has discovered a new world on the edge of the Milky Way – potentially confirming the ‘Planet X’ theory. Beyond Neptune, a smaller ‘ninth’ planet has been identified in the Kuiper Belt. If ...

Astronomers used a telescope in Hawaii to find a new object on the outer edges of our solar system, helping to fuel evidence of a long-standing theory about Planet Nine, or Planet X. For years, ...

Despite the lack of a dedicated mission to the planet, scientists have learned plenty through ground observations and space telescopes Shi En Kim - Reporter A photo of Neptune, taken by the Voyager 2 ...