The strange blend of surface chemistry on Nix and Hydra raises big question about the evolution of the Pluto system.

This 'Kuiper Belt' of minor planets beyond Neptune revolutionised our understanding of the solar system's formation and finally explained the origin of the enigmatic outer planet Pluto. This is the ...

Pluto has had a tough couple of decades. Formerly the ninth planet in our solar system, Pluto was demoted in 2006 to a “dwarf ...

New exhibit to replace Greenbelt Planet Walk with a new trail through Julia Davis Park — but this time, with one less member ...

Test your knowledge on our solar system, from the biggest and smallest planets to the behemoth mountain on Mars.

A new paper discusses the possible existence of an unseen planet in the outer solar system, the so-called "Planet X" or ...

The possibility that there might be a large, unknown planet lurking in the outer Solar System far beyond Pluto has long been a staple of science fiction. But for the past decade, astronomers have been ...

Named for the maiden-snatching, shadow-dwelling god of the underworld, the small but mighty planet Pluto is associated with destruction, subversion, depth, intensity, primal urges, the taboo ...

In astronomy, what does retrograde mean? And what connection does it have to astrology? We explain how planets move across ...