Eris

Eris is a Kuiper Belt object that was found on January 5, 2005.^[1]^[2]

Eris's average distance from Sol, our sun, is 68.5 astronomical units.^[2] It takes 557 years to complete one revolution around Sol. When it was first discovered it was believed to be significantly larger than Pluto. More recent measurements put it at just slightly smaller than Pluto.

Eris has a moon, Dysnomia, which completes its orbit around Eris in 16 days.^[2]

References

↑ Luis Espinoza (2006-04-11). "Artist's Concept of Kuiper Belt Object 2003 UB313 (Non-Annotated)". NASA Science. Retrieved 2026-07-09.
↑ ^2.0 ^2.1 ^2.2 "Eris". NASA Science. 2017-11-15. Archived from the original on 2026-07-04. Retrieved 2026-07-09. The discovery of Eris help trigger a debate in the scientific community that led to the International Astronomical Union's decision in 2006 to clarify the definition of a planet. Pluto, Eris, and other similar objects are now classified as dwarf planets.

[NasaEris2006-04-11-1] Luis Espinoza (2006-04-11). "Artist's Concept of Kuiper Belt Object 2003 UB313 (Non-Annotated)". NASA Science. Retrieved 2026-07-09.

[NasaEris2017-11-15-2] 2.0 ^2.1 ^2.2 "Eris". NASA Science. 2017-11-15. Archived from the original on 2026-07-04. Retrieved 2026-07-09. The discovery of Eris help trigger a debate in the scientific community that led to the International Astronomical Union's decision in 2006 to clarify the definition of a planet. Pluto, Eris, and other similar objects are now classified as dwarf planets.

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