Eris size and scale context

Eris is a distant dwarf planet in the scattered disk beyond Neptune. Its discovery helped trigger the 2006 planet-definition debate, and its tiny moon Dysnomia lets astronomers measure its mass. Read its scale context, comparisons, and journey links on the canonical object page.

HaumeaDwarf planet·2,322 km

ErisDwarf planet·2,326 km

PlutoDwarf planet·2,380 km

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Dwarf planets

Haumea

Haumea is a dwarf planet in the Kuiper Belt with a noticeably stretched silhouette. Its rapid rotation makes it one of the most unusual large bodies in the outer Solar System, and it also has two moons and a ring. The odd system is likely the aftermath of a major collision early in Haumea’s history.

Scale fact2,322 kmmaximum extent

Object class: Dwarf planet
Mass: ~0.00067 Earth masses
Host: Sun
Estimated age: ~4.5 billion years
Composition: Rock and water ice

Dwarf planets

Eris

Eris is a distant dwarf planet in the scattered disk beyond Neptune. Its discovery helped trigger the 2006 planet-definition debate, and its tiny moon Dysnomia lets astronomers measure its mass.

Scale fact2,326 kmmean diameter

Object class: Dwarf planet
Mass: ~0.0028 Earth masses
Host: Sun
Estimated age: ~4.5 billion years
Composition: Rock and ice

Dwarf planets

Pluto

Pluto is an icy dwarf planet with a surprisingly active surface and atmosphere. New Horizons found nitrogen-ice glaciers flowing across its plains and blue hazes in its sky, showing that even the Kuiper Belt can host dynamic worlds.

Scale fact2,380 kmdiameter

Object class: Dwarf planet
Mass: ~0.0022 Earth masses
Host: Sun
Estimated age: ~4.5 billion years
Composition: Rock, water ice, nitrogen and methane ices
Temperature: ~44 K mean surface