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.

Dysnomia, is a moon of the dwarf planet Eris. The satellite is about 60 times fainter than Eris, and its diameter is estimated to be approximately eight times smaller. Astronomers now know that three ...

University of California, Santa Cruz Professor of Planetary Sciences Francis Nimmo recently co-authored a Science Advances paper about the internal structure of the dwarf planet Eris. Eris is about ...

Caroline McCarthy, a CNET News staff writer, is a downtown Manhattanite happily addicted to social-media tools and restaurant blogs. Her pre-CNET resume includes interning at an IT security firm and ...

In the outer Solar System, the dwarf planet Eris is locked in a mutual dance with its moon Dysnomia 1. Eris, the most massive object known in the Solar System beyond Neptune, is so distant that it ...

Two nearly-identically sized worlds — Eris and Pluto — float distantly in the same frozen region of our outer solar system. A NASA spacecraft has visited Pluto, but not Eris, and each is so distant ...

Eris was one of the first dwarf planets to be discovered in the solar system. It is almost the same size as Pluto, and its discovery directly led to the former ninth planet's demotion. Eris also has a ...

The International Astronomical Union has announced that the dwarf planet known as Xena since its 2005 discovery has been named Eris, after the Greek goddess of discord. Eris's moon will be known as ...

This artist's impression shows the distant dwarf planet Eris. New observations have shown that Eris is smaller than previously thought and almost exactly the same size as Pluto. Eris is extremely ...