The dwarf planet formerly known as Xena received a new name Thursday, while Pluto was given a number to reflect the loss of its status as a planet. Michael E. Brown, a professor of planetary ...

Eris is more massive than Pluto but has a smaller volume. It has only one known Moon, called Dysnomia, and it orbits the Sun in just over 559 years. At its closest approach, ...

The observations show that Eris is an almost perfect twin of Pluto in size and appears to be covered in a layer of ice. Skip to main content. ... Eris's mass is 1.66 x 10 22 kg, ...

That means Pluto is bigger than Eris, is the largest object in the Kuiper Belt and the biggest dwarf planet – though there could be hundreds or thousands more out there waiting to be discovered.

For Stern, Pluto, Eris and similar bodies actually represent the dominant class of planets in the solar system. But they're all planets of one type or another.

Close to 18 years ago, astronomers spotted a miniature, icy world named Eris billions of miles beyond Neptune. But unlike its dwarf planet cousin Pluto — which New Horizons promoted to a rich ...

But are these really "planets," or was Pluto merely the first discovery of an entirely new class of objects? In 2006, the International Astronomical Union, the gatekeepers of astronomical nomenclature ...

Tim DeBenedictis is the lead developer of the SkySafari line of iOS and Android apps at Simulation Curriculum, the makers of Starry Night, SkySafari and the free Pluto Safari app. The ...

The observations show that Eris is an almost perfect twin of Pluto in size and appears to be covered in a layer of ice. Results will be published in the Oct. 27 issue of the journal Nature.

Eris appears to have a very reflective surface, suggesting that it is uniformly covered in a thin layer of ice, probably a frozen atmosphere. The results will be published in the 27 October 2011 ...

[4] Eris’s mass is 1.66 x 10^22 kg, corresponding to 22% of the mass of the Moon. [5] For comparison, the Moon’s density is 3.3 grams per cm^3, and water’s is 1.0 gram per cm^3.