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ERIS

A distant dwarf planet beyond Neptune, one of the most massive known objects in the scattered disc and a world that helped redefine the Solar System.
THE DISTANT WORLD
Eris is a dwarf planet located far beyond Neptune in a region of the Solar System known as the scattered disc. It was discovered in 2005 by a team led by astronomer Mike Brown. Its discovery was one of the major events that led to the reclassification of Pluto as a dwarf planet in 2006. Eris is slightly smaller in diameter than Pluto, but its mass is slightly greater. It has an extremely distant and elongated orbit around the Sun. Eris takes more than five centuries to complete one orbit. The dwarf planet has one known moon, Dysnomia, which helped astronomers determine Eris's mass.
~2,326 km
DIAMETER
~558 YEARS
ORBITAL PERIOD
~68 AU
AVERAGE DISTANCE FROM SUN
2005
DISCOVERED
1
KNOWN MOON
DWARF PLANET
CLASSIFICATION
ERIS FEATURES
DYSNOMIA
Eris has one known moon named Dysnomia. Its orbit helped scientists measure the mass of Eris.
SCATTERED DISC
Eris travels through the distant scattered disc, far beyond the main planetary region of the Solar System.
PLUTO'S RIVAL
The discovery of Eris forced astronomers to reconsider what should officially count as a planet.
DID YOU KNOW?
Eris is so far from the Sun that it takes about 558 years to complete a single orbit.
ORBONIX · SOLAR SYSTEM
DWARF PLANET · ERIS