WASHINGTON (Reuters) - Dwarf planet Eris, similar in size to its better-known cosmic cousin Pluto, has remained an enigma since being discovered in 2005 lurking in the solar system's far reaches.

When you buy through links on our articles, Future and its syndication partners may earn a commission. An illustration of confirmed dwarf planets and their moons. From left to right: Pluto (with ...

Pluto's days, though they drag on a bit at around 153 hours, are nothing compared to its years. Pluto's orbit takes 248 Earth ...

A new dwarf planet has been discovered in the icy realms of space beyond Neptune, researchers said Monday. An international team of astronomers spotted the tiny world using the Canada-France-Hawaii ...

Pluto sits far out in the Solar System, small and dim, moving at a pace that barely fits human timelines. It was found in ...

Ever since Pluto was fatefully downgraded from a planet to a dwarf planet, our celestial backyard has become quite semantically confounding. A newly discovered object only adds to this cosmic ...