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 ...

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 ...

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.

January 5, 2005, is an astronomical anniversary that is not really marked but should be. It saw the discovery of dwarf planet ...

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 ...

PASADENA, Calif.–Die-hard Pluto fans still seeking redemption for their demoted planet have cause for despair this week. New data shows that the dwarf planet Eris is 27 percent more massive than Pluto ...

Three times more distant from the Sun than Pluto (almost 10 billion miles), Eris is the largest dwarf planet in the Solar System. It takes Eris more than twice as long to orbit the Sun as Pluto (about ...

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 ...

(Above: An artist concept of the dwarf planet Eris. The sun is the small star in the distance. Courtesy NASA/JPL-Caltech) (WHTM) — In 2005 the team of Mike Brown, Chad Trujillo and David Rabinowitz ...

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 ...

Eris, named after the goddess of strife and discord, just won't leave Pluto alone. Its discovery (at the time, it went by the less appealing name 2003 UB313) prompted a reevaluation of what it meant ...