Astronomy · Dwarf Planets
Eris
The distant dwarf planet that reshaped the definitions.
- Location
- Scattered disk, far beyond Neptune
- Mass
- Among the most massive known dwarf planets
- Moon
- Dysnomia
- Significance
- Its discovery spurred the 2006 planet definition
NASA/JPL/Caltech · NASA media (public domain)
A distant, massive body
Eris is a dwarf planet in the scattered disk, a region of icy bodies on far-flung orbits beyond the main Kuiper Belt. It is one of the most massive dwarf planets known, comparable to Pluto.
Why Eris mattered
Because Eris rivaled Pluto in size and mass, its discovery forced astronomers to decide whether such bodies should be called planets. The result was the 2006 definition that created the 'dwarf planet' category and reclassified Pluto.
Eris and Dysnomia
Eris has a small moon, Dysnomia, whose orbit allowed astronomers to measure Eris's mass precisely. Eris remains one of the most distant readily studied objects of the Solar System.
Knowledge connections
How this connects across Asteria Star — scientific, cultural, and astrological links are kept separate.
Scientific connections
- Part ofSolar System
Related
- Member of groupScattered Disc