As of 2026-07-08, Vanth tops the list with 480 km.
- #1 Vanth — 480 km
natural satellite orbiting 90482 Orcus
Vanth is the only known moon of the large trans-Neptunian dwarf planet Orcus. It was discovered by Michael Brown and Terry-Ann Suer using images taken by the Hubble Space Telescope on 13 November 2005. The moon has a diameter of 443 km (275 mi), making it about half the size of Orcus and the third-largest moon of a trans-Neptunian object. Read more on Wikipedia.
Wikidata - #2 Ilmarë — 400 km
moon of 174567 Varda
Ilmarë, formal designation (174567) Varda I, is the only known moon of the large Kuiper belt object 174567 Varda. It was discovered by Keith Noll et al. in 2009, at a separation of about 0.12 arcsec, using discovery images taken by the Hubble Space Telescope on 26 April 2009, and reported in 2011. Read more on Wikipedia.
Wikidata - #3 Actaea — 390 km
moon of Salacia
Actaea, formal designation (120347) Salacia I, is the only known moon of the large classical Kuiper belt object 120347 Salacia. It was discovered by Keith S. Noll, Harold F. Levison, Denise C. Stephen and William M. Grundy using discovery images taken by the Hubble Space Telescope on 21 July 2006. Read more on Wikipedia.
Wikidata - #4 Dysnomia — 320 km
moon of the dwarf planet Eris
Dysnomia, formal designation (136199) Eris I, is the only known moon of the dwarf planet Eris and is the second-largest known moon of a dwarf planet, after Pluto I Charon. It was discovered in September 2005 by Mike Brown and the Laser Guide Star Adaptive Optics (LGSAO) team at the W. M. Keck Observatory. It carried the provisional designation of S/2005 (2003 UB313) 1 until it was officially named Dysnomia (from the Ancient Greek word Δυσνομία (Dysnomía) meaning anarchy/lawlessness) in... Read more on Wikipedia.
Wikidata - #5 Moon of 38628 Huya — 210 km
moon of 38628 Huya
The Kuiper belt object 38628 Huya has a single known natural satellite or moon, which as of 2025 has no official designation or name. Huya and its moon form a binary system, and are together referred to as the Huya system. The moon was discovered by a team led by Keith Noll using Hubble Space Telescope images taken on 6 May 2012, and confirmed in reexamination of archival Hubble imagery from 30 June and 1 July 2002. The discovery was reported to the International Astronomical Union and was... Read more on Wikipedia.
Wikidata - #6 Xiangliu — 200 km
moon of 225088 Gonggong
Xiangliu, formal designation 225088 Gonggong I, is the only known moon of the scattered-disc dwarf planet Gonggong. It was discovered by a team of astronomers led by Csaba Kiss during an analysis of archival Hubble Space Telescope images of Gonggong. The discovery team had suspected that the slow rotation of Gonggong was caused by tidal forces exerted by an orbiting satellite. Xiangliu was first identified in archival Hubble images taken with Hubble's Wide Field Camera 3 on 18 September 2010.... Read more on Wikipedia.
Wikidata - #7 Gǃòʼé ǃHú — 138 km
moon of (229762) Gǃkúnǁʼhòmdímà
229762 Gǃkúnǁʼhòmdímà (provisional designation 2007 UK126) is a large binary trans-Neptunian object and dwarf planet candidate in the scattered disc, located in the outermost region of the Solar System. It was discovered on 19 October 2007 by American astronomers Megan Schwamb, Michael Brown, and David Rabinowitz at the Palomar Observatory in California. Read more on Wikipedia.
Wikidata - #8 Paha — 135 km
moon of 47171 Lempo
47171 Lempo, or as a binary (47171) Lempo–Hiisi (provisional designation 1999 TC36), is a triple trans-Neptunian object in the Kuiper belt, located in the outermost regions of the Solar System. It was discovered on 1 October 1999, by American astronomers Eric Rubenstein and Louis-Gregory Strolger during an observing run at Kitt Peak National Observatory in Arizona, United States. Rubenstein was searching images taken by Strolger as part of their Nearby Galaxies Supernova Search project. It is... Read more on Wikipedia.
Wikidata - #9 ǃHãunu — 122 km
moon of (469705) ǂKá̦gára
This is a list of trans-Neptunian objects (TNOs), which are minor planets in the Solar System that orbit the Sun at a greater distance on average than Neptune, which means all of their orbits have a semi-major axis greater than 30.1 astronomical units (AU). The Kuiper belt, scattered disc, and Oort cloud are three conventional divisions of this volume of space. As of May 2026, the catalog of minor planets contains 1,049 numbered TNOs. In addition, there are 4,969 unnumbered TNOs, which have... Read more on Wikipedia.
Wikidata - #10 Sawiskera — 120 km
the large moon of (88611) Teharonhiawako
88611 Teharonhiawako (provisional designation 2001 QT297) is a trans-Neptunian object and a member of the cold classical Kuiper belt. Teharonhiawako was discovered on 20 August 2001, by the Deep Ecliptic Survey, and its companion, Sawiskera, was identified a month later. The primary is named after Teharonhia꞉wako, a god of maize in the Iroquois creation myth, while the secondary is named after his evil twin brother Sawiskera. The objects were named in 2007. Read more on Wikipedia.
Wikidata