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.

The first Eris rocket from GIlmour Space Technologies lifts off July 29 (U.S. time) on a short-lived test flight. Credit: GIlmour Space Technologies WASHINGTON — The first flight of an orbital rocket ...

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 ...

New models show Eris is behaving less like a solid, rocky world and more like "soft cheese." When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

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 ...