Eris_(dwarf_planet) - Wikiparency

# Eris (dwarf planet)  **Microsim — three.js (Wikitube framework):** *Eris in the Solar System explorer* <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/solar/Solar_System.html?obj=Eris&embed=1" data-title="Eris in the Solar System explorer"></div> *The Solar System explorer locked on this article's state (`?obj=Eris`); every object and population of the [[PORTAL_Solar_System|Solar System portal]] has its own state in the same scene.*  *Try: drag the year slider to 1977 to find Eris near the far end of its orbit, almost 98 AU from the Sun; drag to an edge-on view to see its orbit climb 44° out of the plane of the planets; then set the speed to 100 years/s and watch it take more than five seconds for one lap while Pluto goes round more than twice.* **Eris** (minor-planet number 136199) is the most massive known [[Dwarf_planet|dwarf planet]] and the second-largest by volume, a bright, icy [[Trans-Neptunian_object|trans-Neptunian object]] of the [[Scattered_disc|scattered disc]].[^sicardy2011][^holler2021] It is 2,326 km across, a little smaller than [[Pluto]], but about 27 percent more massive, with a mass of 1.65 × 10²² kg, about 0.28 percent of [[Earth]]'s (derived).[^sicardy2011][^holler2021][^nasa-fs] Its eccentric orbit, inclined 44° to the [[Ecliptic|ecliptic]], carries it between about 38 and 98 AU from the [[Sun]].[^sbdb] It has one confirmed moon, Dysnomia, and may have another.[^brown2006moons][^ortiz2025] Michael Brown, Chad Trujillo and David Rabinowitz found Eris in January 2005 on images taken at Palomar Observatory in 2003, and announced it in July 2005.[^brown2005] Because it then seemed larger than Pluto, NASA described it as a tenth planet; the debate that followed led the IAU to define the word planet in August 2006, making Eris, Pluto and [[Ceres_(dwarf_planet)|Ceres]] dwarf planets.[^jpl2005][^iau2006] It was named the following month after the Greek goddess of strife and discord.[^iauc8747] Leaving aside long-period comets, no natural body was known to lie farther from the Sun than Eris and its moon until 2018.[^carnegie2018] The explorer at the top of this page is locked on Eris: it draws the orbit from JPL's Small-Body Database, between 38.2 and 97.7 [[Astronomical_unit|AU]] on an orbit tilted 44°; the body is enlarged for visibility, and Dysnomia is not drawn.[^sbdb] ## Discovery Brown's team had spent several years scanning the sky for large bodies in the outer Solar System with the 1.2-metre Samuel Oschin Schmidt telescope at Palomar Observatory, and had already found several large trans-Neptunian objects, among them [[Quaoar]], [[Orcus_(dwarf_planet)|Orcus]] and [[Sedna_(dwarf_planet)|Sedna]].[^schilling2009] The images that contain Eris were taken on 21 October 2003, but the object was missed: to limit false detections, the team's software ignored anything moving slower than 1.5 arcseconds per hour. After Sedna turned up moving at 1.75 arcseconds per hour, the team went back through old fields with a lower threshold, checking the slower candidates by eye, and on 5 January 2005 found Eris creeping against the background stars.[^brown2005] The slow motion itself implied a great distance, and follow-up observations fixed a preliminary orbit.[^brown2005] The team intended to wait for further measurements before announcing Eris and [[Makemake]], but when a Spanish group announced [[Haumea]], another object Brown's team had been following, on 27 July 2005, they announced both on 29 July.[^brown-eris][^latimes2005] Searches of older photographs later found Eris on plates as early as 3 September 1954.[^sbdb] In October 2005 further observations revealed a moon, and its orbit gave Eris's mass in 2007: 1.66 × 10²² kg, clearly more than Pluto's.[^brown2006moons][^brown2007] ## Name Eris takes its name from the Greek goddess of strife and discord.[^usgs2006] The discovery team proposed it on 6 September 2006, and it was assigned on 13 September, ending more than a year during which the object had carried only its provisional designation, 2003 UB313.[^iauc8747][^brown-eris] Two pronunciations are heard, with a short or a long first vowel.[^brown-eris] ### Xena Because different naming procedures apply to planets and to minor planets, no name could be chosen until the IAU had decided in August 2006 what kind of object this was.[^iauc8747] In the meantime the public came to know it as Xena, the discovery team's internal nickname, taken from the title character of the television series *Xena: Warrior Princess*; the team had reportedly reserved it for the first body they found larger than Pluto.[^brown-eris] ### Choosing an official name According to the science writer Govert Schilling, Brown first wanted the name Lila, after a concept in Hindu mythology describing the cosmos as the play of Brahman, and pronounced like the name of his newborn daughter, Lilah. He had been criticised for publicising Sedna's name before it was approved, and when the address of his discovery web page, which ended in "planetlila", became public in the confusion over Haumea, he dropped the name rather than risk further offence.[^schilling2009] Persephone, the wife of the god Pluto, was also considered and topped a readers' poll by *New Scientist*, in which "Xena" came fourth, but an asteroid, 399 Persephone, already had that name.[^brown-eris][^oneill2005] Since the object had been treated as a planet for so long, Brown wanted it to carry a classical Greek or Roman name, as the planets do; most such names had already gone to asteroids, but Eris had not.[^brown-eris] "Eris caused strife and discord by causing quarrels among people," Brown said in 2006, "and that's what this one has done too."[^reuters2006] The IAU accepted the name on 13 September 2006.[^iauc8747] Planetary symbols are discouraged in astronomy, but NASA has used the Hand of Eris, a sign taken from Discordianism, a religion centred on the goddess, to represent the dwarf planet.[^jpl2015] ## Classification By its orbit Eris is a scattered-disc object, one of the bodies thought to have been thrown from the [[Kuiper_belt|Kuiper belt]] region onto distant, eccentric orbits by encounters with [[Neptune]] while the Solar System was forming. Its high inclination is unusual even among scattered objects, but models suggest that bodies from near the inner edge of the primordial belt were scattered onto more steeply inclined orbits than those from farther out.[^gomes2005] NASA and many news reports initially called Eris the "tenth planet", because it appeared larger than Pluto.[^jpl2005] The question of its status, and the long-running debate about Pluto's, led the IAU to appoint a group of astronomers to draft a precise definition of a planet. The [[IAU_definition_of_planet|definition adopted on 24 August 2006]] requires a planet to have [[Clearing_the_neighbourhood|cleared the neighbourhood]] of its orbit, which Eris and Pluto have not, so both became dwarf planets.[^iau2006] Brown has since said he approves of the result.[^britt2006] The IAU then added Eris to its catalogue of minor planets as (136199) Eris.[^iauc8747] ## Orbit Eris orbits the Sun in about 560 years, more than twice Pluto's period. Its orbit has a semi-major axis of 67.9 AU and an eccentricity of 0.44, carrying it between about 38.2 AU at perihelion and 97.7 AU at aphelion, and is tilted about 44° to the ecliptic.[^sbdb] Numerical integration with JPL's Horizons system shows that Eris last passed perihelion around 1699 and aphelion around 1977, and will return to perihelion on 6 December 2257.[^horizons] In February 2016 it was 96.3 AU from the Sun, more than three times Neptune's distance.[^astdys] Its perihelion distance, near 38 AU, is typical of scattered objects: inside the aphelion of Pluto, but far enough from Neptune's orbit, at about 30 AU, to escape direct encounters with the planet.[^trujillo2000][^sbdb] Pluto, by contrast, has a smaller and less tilted orbit that crosses Neptune's, and is protected by resonance.[^malhotra1997] In 2007 Eris shone at magnitude 18.7, within reach of large amateur telescopes with electronic cameras.[^lin2007] It was found late because its steep inclination keeps it far from the ecliptic, where searches for distant bodies had concentrated.[^brown2005] Its steep orbit also takes it through few zodiacal constellations: it lies in Cetus in 2026, will enter Pisces in 2036 and Aries in 2065, and will later move into the northern sky.[^horizons] The explorer draws the present osculating orbit from JPL elements, so the 44° tilt and the long aphelion excursion are real; the body is enlarged for visibility.[^sbdb] ## Size, mass and density Early measurements suggested that Eris was larger than Pluto. Hubble Space Telescope imaging in 2005 gave a diameter of about 2,400 km, and thermal measurements gave about 3,000 km from the IRAM radio telescope and about 2,600 km from Spitzer.[^brown2006size][^bertoldi2006][^stansberry2008] A stellar occultation on 6 November 2010, observed from Chile and one of the most distant ever recorded from Earth, settled the size at 2,326 ± 12 km, slightly smaller than Pluto's 2,377 km.[^beatty2010][^sicardy2011][^nimmo2017] The occultation also gave a geometric albedo of 0.96, one of the highest in the Solar System, which may mean that the surface ices are renewed as Eris's changing distance from the Sun drives cycles of sublimation and condensation.[^sicardy2011][^brown2006size] The mass is known more precisely than the size, from the orbit of Dysnomia through [[Kepler's_laws_of_planetary_motion|Kepler's third law]]. Brown and Schaller derived 1.66 × 10²² kg in 2007 from a period of 15.774 days; Holler and colleagues refined it in 2021 to 1.6466 × 10²² kg.[^brown2007][^holler2021] With the occultation diameter, Eris's [[Density|density]] is 2.52 g/cm³, considerably higher than Pluto's 1.85 g/cm³, which means Eris is made mostly of rock.[^sicardy2011][^fs-pluto] Models of internal heating by [[Radioactive_decay|radioactive decay]] suggest that Eris could hold a layer of liquid water at the boundary between its rocky core and icy mantle, and tidal heating by Dysnomia could help preserve it.[^hussmann2006][^saxena2018] The chemistry of its surface methane, discussed below, has also been read as a sign of internal activity.[^grundy2024] After New Horizons measured Pluto's size in 2015, Eris became the tenth-largest known body orbiting the Sun directly, by volume, and the ninth by mass.[^nasa2015][^csa2020] ## Surface and atmosphere On 25 January 2005, days after the discovery, the team took infrared spectra of Eris with the 8-metre Gemini North telescope and found methane ice, showing a surface like those of Pluto and of Neptune's moon [[Triton_(moon)|Triton]], the only other bodies then known to have it.[^gemini2005] Visible spectra from 2006 also showed evidence for [[Nitrogen|nitrogen]] ice.[^licandro2006] Spectra from the James Webb Space Telescope in 2022 detected deuterated methane and substantial nitrogen ice. The methane's deuterium-to-hydrogen ratio is lower than in comets, which Grundy and colleagues interpreted as a sign that the methane was produced inside Eris, by geochemical processes in a warm interior, rather than inherited unchanged from the solar nebula.[^grundy2024] Unlike the reddish, mottled surfaces of Pluto and Triton, Eris looks almost white and uniform.[^brown-eris] On Pluto, dark tholin deposits absorb sunlight, warm up and shed their methane frost, which keeps them dark; at Eris's much greater distance even dark patches are cold enough for methane to freeze onto them, so a uniform layer of frost covers any tholins.[^brown2005] Hofgartner and colleagues showed that the transport of methane through a local, collisional atmosphere during the warmer part of the orbit could keep resurfacing Eris, and Grundy and Umurhan suggested that, like Pluto's Sputnik Planitia, Eris's surface could be renewed by slow convection in a thick layer of nitrogen and methane ice.[^hofgartner2019][^grundy2017] JWST found no ethane, a product of methane broken down by radiation, which supports a surface that is continually refreshed.[^grundy2024] Surface temperatures are estimated to range from about 30 K to 56 K over the orbit.[^brown-eris] Near perihelion some ice may warm enough to sublimate into a thin atmosphere. The survival of volatile methane and nitrogen means either that Eris has always stayed cold enough to retain them or that an internal source replaces the gas it loses.[^hofgartner2019] This contrasts with Haumea, which shows water ice but no methane.[^tegler2007] ## Rotation Because its surface is so uniform, Eris's brightness barely changes as it turns, which long made the rotation period hard to measure; estimates ranged from tens of hours to several days.[^duffard2008] Long-term monitoring from the ground and from space by Szakáts and colleagues showed in 2023 that Eris rotates once every 15.78 days, the same period as Dysnomia's orbit: Eris is tidally locked to its moon.[^szakats2023] Since Dysnomia is also expected to be locked to Eris, the pair is the second known case of mutual tidal locking, after Pluto and [[Charon_(moon)|Charon]].[^szakats2023] The tilt of Eris's axis has not been measured directly, but it is reasonable to assume that the equator lies in the plane of Dysnomia's orbit, inclined about 78° to the ecliptic. In that case most of the northern hemisphere is currently sunlit, with about 30 percent of it in continuous daylight around 2018.[^holler2018] ## Satellites ### Dysnomia The laser guide star adaptive optics system of the Keck telescopes in Hawaii, newly commissioned in 2005, was turned that year on the four brightest trans-Neptunian objects. Images taken on 10 September revealed a moon of Eris.[^brown2006moons] Following the "Xena" nickname, the team called it "Gabrielle", after the character's companion in the television series. When Eris received its name, the moon was named Dysnomia, after Eris's daughter, the goddess of lawlessness; Brown chose it partly because it resembles the name of his wife, Diane, and it keeps an unintended echo of Xena's actress, Lucy Lawless.[^tytell2006] Dysnomia orbits about 37,300 km from Eris every 15.79 days.[^holler2021] ALMA measurements by Brown and Butler gave a diameter of about 615 km and a mass of about 8 × 10¹⁹ kg, making it one of the largest moons of any dwarf planet.[^brown2023] ### Possible second moon Holler and colleagues found in 2021 that Dysnomia's orbit is not a fixed ellipse but precesses, which requires a perturbing influence: an oblate Eris, a non-spherical Dysnomia, or an unseen inner moon.[^holler2021] Brozović and Jacobson's preliminary analysis in 2023 favoured an unseen moon in resonance with Dysnomia.[^brozovic2023] Photometry from the Gaia spacecraft shows a small brightness variation of 0.031 magnitudes with a period of 18.853 hours that neither Eris's nor Dysnomia's rotation explains. Ortiz and colleagues proposed in 2025 that it could come from a large unseen moon, roughly 1,000 km across, orbiting about 5,050 or 8,010 km from Eris; such a moon could also account for Dysnomia's precession and for some of Eris's high estimated density and albedo, although it would not explain why Eris is locked to Dysnomia rather than to the closer moon.[^ortiz2025] | Body | Diameter (km) | Semi-major axis (km) | Mass (kg) | Discovered | |---|---|---|---|---| | Eris | 2,326[^sicardy2011] | — | 1.6466 × 10²²[^holler2021] | 5 January 2005 | | Dysnomia | ≈615[^brown2023] | 37,273[^holler2021] | ≈8 × 10¹⁹[^brown2023] | 10 September 2005 | ## Exploration No spacecraft has visited Eris. [[NASA]]'s New Horizons observed it from afar in May 2020, during its extended mission. The spacecraft was then 112 AU from Eris, farther than Earth's 96 AU, but its position in the outer Solar System let it see Eris at high phase angles unobtainable from Earth and so measure how the surface scatters light.[^verbiscer2022] Eris has been evaluated as a candidate target in studies of follow-on missions to the Kuiper belt, and McGranaghan and colleagues calculated that a flyby launched on 3 April 2032 or 7 April 2044 could reach it in 24.66 years using a [[Jupiter]] gravity assist, arriving when it is 92.03 or 90.19 AU from the Sun.[^mcgranaghan2011] ## See also - [[Dwarf_planet]] · [[IAU_definition_of_planet]] · [[Clearing_the_neighbourhood]] - [[Scattered_disc]] · [[Trans-Neptunian_object]] - [[Pluto]] · [[Makemake]] · [[Haumea]] · [[Gonggong_(dwarf_planet)]] - [[PORTAL_Solar_System|Solar System portal]] ## Explanatory notes Derived numbers are computed from the cited values: Eris's mass relative to Pluto, 1.6466 / 1.303 ≈ 1.26, and to Earth, 0.016466 / 5.972 ≈ 0.0028; the orbital period from the JPL value of about 205,000 days, ≈ 561 years, which at 100 years/s gives a lap of about 5.6 seconds; and the ratio of the periods of Eris and Pluto, 561 / 248 ≈ 2.3. ## References [^sbdb]: JPL Small-Body Database, "136199 Eris (2003 UB313)" (orbital elements fetched 2026-09-18). https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=136199 [^horizons]: JPL Solar System Dynamics. "Horizons" ephemerides for 136199 Eris: perihelion around 1699 and on 6 December 2257; constellation positions. https://ssd.jpl.nasa.gov/horizons/ [^astdys]: AstDyS. "(136199) Eris ephemerides". Department of Mathematics, University of Pisa. https://newton.spacedys.com/astdys/index.php?pc=1.1.3.0&n=Eris [^nasa-fs]: NASA NSSDCA. "Planetary Fact Sheet". https://nssdc.gsfc.nasa.gov/planetary/factsheet/ (fetched 2026-09-18). [^fs-pluto]: Williams, D. R. "Pluto Fact Sheet". NASA NSSDCA, last updated 11 January 2024. https://nssdc.gsfc.nasa.gov/planetary/factsheet/plutofact.html [^sicardy2011]: Sicardy, B.; Ortiz, J. L.; Assafin, M.; et al. (2011). "A Pluto-like radius and a high albedo for the dwarf planet Eris from an occultation". *Nature* 478: 493–496. https://doi.org/10.1038/nature10550 [^holler2021]: Holler, B. J.; Grundy, W. M.; Buie, M. W.; Noll, K. S. (2021). "The Eris/Dysnomia system I: The orbit of Dysnomia". *Icarus* 355: 114130. https://doi.org/10.1016/j.icarus.2020.114130 [^brown2005]: Brown, M. E.; Trujillo, C. A.; Rabinowitz, D. L. (2005). "Discovery of a planetary-sized object in the scattered Kuiper belt". *The Astrophysical Journal* 635: L97–L100. https://doi.org/10.1086/499336 [^brown-eris]: Brown, M. E. (2006). "The discovery of 2003 UB313 Eris, the largest known dwarf planet". California Institute of Technology. http://www.gps.caltech.edu/~mbrown/planetlila/ [^latimes2005]: Maugh, T. H.; Johnson, J. (16 October 2005). "His stellar discovery is eclipsed". *Los Angeles Times*. https://www.latimes.com/archives/la-xpm-2005-oct-16-me-planet16-story.html [^brown2006moons]: Brown, M. E.; van Dam, M. A.; Bouchez, A. H.; et al. (2006). "Satellites of the largest Kuiper belt objects". *The Astrophysical Journal* 639: L43–L46. https://doi.org/10.1086/501524 [^brown2007]: Brown, M. E.; Schaller, E. L. (2007). "The mass of dwarf planet Eris". *Science* 316: 1585. https://doi.org/10.1126/science.1139415 [^ortiz2025]: Ortiz, J. L.; Morales, N.; Gutiérrez, P. J. (2025). "Analysis of the Gaia DR3 photometry of the dwarf planet Eris". *Monthly Notices of the Royal Astronomical Society: Letters* 538: L37–L42. https://doi.org/10.1093/mnrasl/slaf005 [^jpl2005]: NASA Jet Propulsion Laboratory (29 July 2005). "NASA-funded scientists discover tenth planet". News release 2005-126. http://www.jpl.nasa.gov/news/news.cfm?release=2005-126 [^iau2006]: International Astronomical Union (24 August 2006). "IAU 2006 General Assembly: Resolutions 5 and 6". https://www.iau.org/static/resolutions/Resolution_GA26-5-6.pdf [^iauc8747]: Green, D. W. E. (13 September 2006). "(134340) Pluto, (136199) Eris, and (136199) Eris I (Dysnomia)". *IAU Circular* 8747. http://www.cbat.eps.harvard.edu/iauc/08700/08747.html [^carnegie2018]: Carnegie Science (17 December 2018). "Discovered: The most-distant Solar System object ever observed". https://carnegiescience.edu/news/discovered-most-distant-solar-system-object-ever-observed [^schilling2009]: Schilling, G. (2009). *The Hunt for Planet X: New Worlds and the Fate of Pluto*. Springer/Copernicus, p. 214. ISBN 978-0-387-77804-4. [^usgs2006]: Blue, J. (14 September 2006). "2003 UB313 named Eris". USGS Astrogeology Research Program. https://astrogeology.usgs.gov/HotTopics/index.php?/archives/211-2003-UB313-named-Eris.html [^oneill2005]: O'Neill, S. (2005). "Your top 10 names for the tenth planet". *New Scientist*. https://www.newscientist.com/article/dn7811-your-top-10-names-for-the-tenth-planet/ [^reuters2006]: Sullivan, A. (15 September 2006). "Xena renamed Eris in planet shuffle". Reuters, via ABC Science. http://www.abc.net.au/science/articles/2006/09/15/1741585.htm [^jpl2015]: NASA Jet Propulsion Laboratory (22 April 2015). "What is a dwarf planet?". https://www.jpl.nasa.gov/infographics/what-is-a-dwarf-planet [^gomes2005]: Gomes, R. S.; Gallardo, T.; Fernández, J. A.; Brunini, A. (2005). "On the origin of the high-perihelion scattered disk: The role of the Kozai mechanism and mean motion resonances". *Celestial Mechanics and Dynamical Astronomy* 91: 109–129. https://doi.org/10.1007/s10569-004-4623-y [^britt2006]: Britt, R. R. (24 August 2006). "Pluto demoted: No longer a planet in highly controversial definition". *Space.com*. http://space.com/scienceastronomy/060824_planet_definition.html [^trujillo2000]: Trujillo, C. A.; Jewitt, D. C.; Luu, J. X. (2000). "Population of the scattered Kuiper belt". *The Astrophysical Journal* 529: L103–L106. https://doi.org/10.1086/312467 [^malhotra1997]: Malhotra, R. (1997). "Pluto's orbit". The Nine Planets. http://www.nineplanets.org/plutodyn.html [^lin2007]: Lin, H.-W.; Wu, Y.-L.; Ip, W.-H. (2007). "Observations of dwarf planet (136199) Eris and other large TNOs on Lulin Observatory". *Advances in Space Research* 40: 238–243. https://doi.org/10.1016/j.asr.2007.06.009 [^brown2006size]: Brown, M. E.; Schaller, E. L.; Roe, H. G.; Rabinowitz, D. L.; Trujillo, C. A. (2006). "Direct measurement of the size of 2003 UB313 from the Hubble Space Telescope". *The Astrophysical Journal* 643: L61–L63. https://doi.org/10.1086/504843 [^bertoldi2006]: Bertoldi, F.; Altenhoff, W.; Weiss, A.; Menten, K. M.; Thum, C. (2006). "The trans-Neptunian object UB313 is larger than Pluto". *Nature* 439: 563–564. https://doi.org/10.1038/nature04494 [^stansberry2008]: Stansberry, J.; Grundy, W.; Brown, M.; et al. (2008). "Physical properties of Kuiper belt and Centaur objects: Constraints from the Spitzer Space Telescope". In *The Solar System Beyond Neptune*. University of Arizona Press, pp. 161–179. Bibcode 2008ssbn.book..161S. [^beatty2010]: Beatty, K. (November 2010). "Former 'tenth planet' may be smaller than Pluto". *New Scientist*. https://www.newscientist.com/article/dn19697-former-tenth-planet-may-be-smaller-than-pluto.html [^nimmo2017]: Nimmo, F.; Umurhan, O.; Lisse, C. M.; et al. (2017). "Mean radius and shape of Pluto and Charon from New Horizons images". *Icarus* 287: 12–29. https://doi.org/10.1016/j.icarus.2016.06.027 [^hussmann2006]: Hussmann, H.; Sohl, F.; Spohn, T. (2006). "Subsurface oceans and deep interiors of medium-sized outer planet satellites and large trans-neptunian objects". *Icarus* 185: 258–273. https://doi.org/10.1016/j.icarus.2006.06.005 [^saxena2018]: Saxena, P.; Renaud, J. P.; Henning, W. G.; Jutzi, M.; Hurford, T. (2018). "Relevance of tidal heating on large TNOs". *Icarus* 302: 245–260. https://doi.org/10.1016/j.icarus.2017.11.023 [^grundy2024]: Grundy, W. M.; Wong, I.; Glein, C. R.; et al. (2024). "Measurement of D/H and ¹³C/¹²C ratios in methane ice on Eris and Makemake: Evidence for internal activity". *Icarus* 411: 115923. https://doi.org/10.1016/j.icarus.2023.115923 [^nasa2015]: NASA (13 July 2015). "How big is Pluto? New Horizons settles decades-long debate". http://www.nasa.gov/feature/how-big-is-pluto-new-horizons-settles-decades-long-debate [^csa2020]: Canadian Space Agency (12 March 2020). "Dwarf planets". https://www.asc-csa.gc.ca/eng/astronomy/solar-system/dwarf-planets.asp [^gemini2005]: Gemini Observatory (2005). "Gemini Observatory shows that '10th planet' has a Pluto-like surface". http://www.gemini.edu/index.php?option=content&task=view&id=142 [^licandro2006]: Licandro, J.; Grundy, W. M.; Pinilla-Alonso, N.; Leisy, P. (2006). "Visible spectroscopy of 2003 UB313: evidence for N₂ ice on the surface of the largest TNO?". *Astronomy & Astrophysics* 458: L5–L8. https://doi.org/10.1051/0004-6361:20066028 [^hofgartner2019]: Hofgartner, J. D.; Buratti, B. J.; Hayne, P. O.; Young, L. A. (2019). "Ongoing resurfacing of KBO Eris by volatile transport in local, collisional, sublimation atmosphere regime". *Icarus* 334: 52–61. https://doi.org/10.1016/j.icarus.2018.10.028 [^grundy2017]: Grundy, W. M.; Umurhan, O. M. (2017). "Are Makemake and Eris Sputnik planets?". *AAS Division for Planetary Sciences meeting* 49, abstract 202.02. Bibcode 2017DPS....4920202G. [^tegler2007]: Tegler, S. C.; Grundy, W. M.; Romanishin, W.; et al. (2007). "Optical spectroscopy of the large Kuiper belt objects 136472 (2005 FY9) and 136108 (2003 EL61)". *The Astronomical Journal* 133: 526–530. https://doi.org/10.1086/510134 [^duffard2008]: Duffard, R.; Ortiz, J. L.; Santos-Sanz, P.; et al. (2008). "A study of photometric variations on the dwarf planet (136199) Eris". *Astronomy & Astrophysics* 479: 877–881. https://doi.org/10.1051/0004-6361:20078619 [^szakats2023]: Szakáts, R.; Kiss, Cs.; Ortiz, J. L.; et al. (2023). "Tidally locked rotation of the dwarf planet (136199) Eris discovered from long-term ground based and space photometry". *Astronomy & Astrophysics* 669: L3. https://doi.org/10.1051/0004-6361/202245234 [^holler2018]: Holler, B. J.; Grundy, W. M.; Buie, M. W.; Noll, K. S. (2018). "Breaking the degeneracy of Eris' pole orientation". *AAS Division for Planetary Sciences meeting* 50, abstract 509.03. Bibcode 2018DPS....5050903H. [^tytell2006]: Tytell, D. (2006). "All hail Eris and Dysnomia". *Sky & Telescope*. http://www.skyandtelescope.com/astronomy-news/all-hail-eris-and-dysnomia/ [^brown2023]: Brown, M. E.; Butler, B. J. (2023). "Masses and densities of dwarf planet satellites measured with ALMA". *The Planetary Science Journal* 4: 193. https://doi.org/10.3847/PSJ/ace52a [^brozovic2023]: Brozović, M.; Jacobson, R. A. (2023). "Revisiting orbit fits for the Eris–Dysnomia system". *Bulletin of the American Astronomical Society* 55: 503.02. https://baas.aas.org/pub/2023n5i503p02/release/1 [^verbiscer2022]: Verbiscer, A. J.; Helfenstein, P.; Porter, S. B.; et al. (2022). "The diverse shapes of dwarf planet and large KBO phase curves observed from New Horizons". *The Planetary Science Journal* 3: 95. https://doi.org/10.3847/PSJ/ac63a6 [^mcgranaghan2011]: McGranaghan, R.; Sagan, B.; Dove, G.; et al. (2011). "A survey of mission opportunities to trans-Neptunian objects". *Journal of the British Interplanetary Society* 64: 296–303. Bibcode 2011JBIS...64..296M. ## External links - NASA Science: Eris. https://science.nasa.gov/dwarf-planets/eris/ - JPL Small-Body Database: 136199 Eris. https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=136199 - Minor Planet Center: (136199) Eris. https://www.minorplanetcenter.net/db_search/show_object?object_id=136199 - Brown, M. E. "The discovery of Eris, the largest known dwarf planet" (Caltech). http://www.gps.caltech.edu/~mbrown/planetlila/ ## Wikipedia : Wikitube **Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Eris_(dwarf_planet)) : [Wikitube](https://en.wikitube.io/wiki/Eris_(dwarf_planet)) · pinned revision [1375002347](https://en.wikipedia.org/w/index.php?oldid=1375002347) · 2026-09-18 ## Previous hub tags Hubs: `Life_Physics`. Portals: [[PORTAL_Solar_System]]. --- *Solar System portal child articles, wave 1 · 2026-09-18 · drafted · row SOL-074 · explorer state `?obj=Eris`.*