(28978) Ixion (ik·sye'·un) is a Kuiper belt object discovered on May 22, 2001 with a diameter of < 822 km and a semimajor axis of about 39.5 AU. Ixion is a Plutino, meaning it has a 3:2 orbital resonance with Neptune. The Deep Ecliptic Survey is a project to find Kuiper belt objects, using the facilities of the National Optical Astronomy Observatory. ... May 22 is the 142nd day of the year in the Gregorian calendar (143rd in leap years). ... 2001: A Space Odyssey. ... The provisional designation of comets and asteroids are similar to each other: they both follow a pattern set in 1925 by the Minor Planet Center of the IAU. Historical designations At first, astronomers strove to assign symbols to the minor planets: 1 Ceres a stylized sickle 2 Pallas a lozenge... Minor planets, or planetoids are minor bodies of the Solar system orbiting the Sun (or of other planetary systems orbiting other stars) that are larger than meteoroids (the largest of which might be taken to be around 10 meters or so across) but smaller than major planets (Mercury having a... In astronomy, a plutino is a trans-Neptunian object that has a 3:2 orbital resonance with Neptune. ... In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... January 30 is the 30th day of the year in the Gregorian calendar. ... The Julian day or Julian day number (JDN) is the number of days that have elapsed since 12 noon Greenwich Mean Time (UT or TT) on Monday, January 1, 4713 BC in the proleptic Julian calendar . ... In astrodynamics, under standard assumptions any orbit must be of conic section shape. ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... The astronomical unit (AU or au or a. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... The orbital period is the time it takes a planet (or another object) to make one full orbit. ... In astronomy, a Julian year is a unit of time defined as exactly 365. ... The orbital speed of a body, generally a planet, a natural satellite, an artificial satellite, or a multiple star, is the speed at which it orbits around the barycenter of a system, usually around a more massive body. ... Inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit and is the angular distance of the orbital plane from the plane of the reference (usually planets equator or the ecliptic), stated in degrees. ... A degree (in full, a degree of arc, arc degree, or arcdegree), usually symbolized °, is a measurement of plane angle, representing 1／360 of a full rotation. ... The Longitude of the ascending node () is one of the orbital elements used to specify the orbit of an object in space. ... The argument of the perihelion is one of the orbital elements describing the orbit of a planet. ... In the study of orbital dynamics the mean anomaly is a measure of time, specific to the orbiting body p, which is a multiple of 2π radians at and only at periapsis. ... For the majority of numbered asteroids, almost nothing is known apart from a few physical parameters. ... A kilometre (American spelling: kilometer), symbol: km is a unit of length in the metric system equal to 1000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ... Mass is a property of physical objects that, roughly speaking, measures the amount of matter they contain. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... ... In physics, for a given gravitational field and a given position, the escape velocity is the minimum speed an object without propulsion, at that position, needs to have to move away indefinitely from the source of the field, as opposed to falling back or staying in an orbit within a... In astronomy, a rotation period is the time an astronomical object takes to complete one revolution around its rotation axis. ... Asteroids are assigned a type based on spectral shape, color, and sometimes albedo. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standardized distance away. ... The albedo is a measure of reflectivity of a surface or body. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... Artists rendering of the Kuiper Belt and more distant Oort cloud. ... May 22 is the 142nd day of the year in the Gregorian calendar (143rd in leap years). ... 2001: A Space Odyssey. ... For the geometric term, see diameter. ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... The astronomical unit (AU or au or a. ... In astronomy, a plutino is a trans-Neptunian object that has a 3:2 orbital resonance with Neptune. ... In celestial mechanics, orbital resonance occurs when two orbiting bodies have periods of revolution that are in a simple integer ratio so that they exert a regular gravitational influence on each other. ... Atmospheric characteristics Surface pressure ≫100 MPa Hydrogen - H2 80% ±3. ...

Little is known about this object. The latest spectroscopy results indicate that the Ixionian surface is a mixture of dark carbon and tholin, which is a heteropolymer formed by irradiation of clathrates of water and organic compounds (such as methane or ethane). A spectroscope is a device which measures the spectrum of light. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... Tholin is a heteropolymer formed by solar ultraviolet irradiation of simple organic compounds such as methane or ethane. ... A heteropolymer, also called a copolymer, is a polymer formed when two different types of monomer are linked in the same polymer chain. ... A clathrate or clathrate compound is a chemical substance consisting of a Greek klethra, meaning bars (in the sense of a lattice). ... Water (from the Old English word wæter; c. ... An organic compound is any member of a large class of chemical compounds whose molecules contain carbon, with the exception of carbides, carbonates, carbon oxides and gases containing carbon. ... R-phrases S-phrases , , , Flash point −188 °C Autoignition temperature 537 °C Explosive limits 5–15% Supplementary data page Structure and properties n, εr, etc. ... R-phrases S-phrases , , , Flash point -135 °C Autoignition temperature 472 °C Explosive limits 3. ...

(28978) Ixion is named after Ixion, a figure from Greek mythology. It previously had the provisional designation 2001 KX₇₆. This article is about the Greek myth. ... Greek mythology comprises the collected narratives of Greek gods, goddesses, heroes, and heroines, originally created and spread within an oral-poetic tradition. ... The provisional designation of comets and asteroids are similar to each other: they both follow a pattern set in 1925 by the Minor Planet Center of the IAU. Historical designations At first, astronomers strove to assign symbols to the minor planets: 1 Ceres a stylized sickle 2 Pallas a lozenge...

Reference

• Pre-print about Ixion's surface from the Planetary Systems Research group of the University of Helsinki.

… | Previous minor planet | 28978 Ixion | Next minor planet | … The University of Helsinki is a university located in Helsinki, Finland. ...

A trans-Neptunian object (TNO) is any object in the solar system which orbits the sun at a greater distance on average than Neptune. ... Artists rendering of the Kuiper Belt and more distant Oort cloud. ... Adjective Plutonian Atmospheric characteristics Atmospheric pressure 0. ... Charon (shar-É™n or karr-É™n, Greek Χάρων) is the largest satellite of Pluto. ... 90482 Orcus (originally known by the provisional designation 2004 DW) is a Kuiper Belt object (KBO) that was discovered by Michael Brown of Caltech, Chad Trujillo of the Gemini Observatory, and David Rabinowitz of Yale University. ... The correct title of this article is (55637) 2002 UX25. ... 20000 Varuna (VAR oo na) is a Kuiper Belt object about 1060 kilometers in diameter, estimated from a combination of thermal and optical measurements. ... The title of this article is incorrect due to technical limitations. ... Artists impression by G. Bacon of STScI / NASA 50000 Quaoar (pronounced kwah·war, kwah·wor, or kwow·ur, Tongva ) [1] is a Trans-Neptunian object orbiting the Sun in the Edgeworth-Kuiper belt. ... 2005 FY9 (also written 2005 FY9), codenamed Easterbunny by its discoverers, is a very large Kuiper belt object discovered on March 31, 2005 by the team led by Michael Brown. ... (55565) 2002 AW197 (also written: (55565) 2002 AW197) is a trans-Neptunian object. ... The scattered disc (or scattered disk) is a distant region of our solar system, thinly populated by a subset of the family of trans-Neptunian objects known as scattered disk objects (SDOs). ... 2003 UB313 (also written 2003 UB313) is a trans-Neptunian object (TNO) which California astronomers at Mount Palomar observatory describe as definitely bigger than the planet Pluto. ... The correct title of this article is 2004 XR190. ... 90377 Sedna is a trans-Neptunian object, discovered by Michael Brown (Caltech), Chad Trujillo (Gemini Observatory) and David Rabinowitz (Yale University) on November 14, 2003. ... Triton (trye-tun, Greek Τρίτων), also designated Neptune I, is the planet Neptunes largest moon. ... See also Lists of astronomical objects Categories: Astronomical objects ... Presentation of the solar system (not to scale) The solar system comprises our Sun and the retinue of celestial objects gravitationally bound to it. ... Below is a list of solar system objects with diameter >500km: The Sun, a spectral class G2 star Mercury Venus Earth Moon Mars Jupiter Io Europa Ganymede Callisto complete list of Jupiters natural satellites Saturn Tethys Dione Rhea Titan Iapetus complete list of Saturns natural satellites Uranus Ariel... This is a list of solar system objects by radius, in decreasing order. ... This is a list of Solar system objects by mass, in decreasing order. ... Pronunciation of Centaurs, Kuiper Belt Objects, and other planetoids of the outer solar system Pronunciation key ... The Minor Planet Center operates at the Smithsonian Astrophysical Observatory (SAO), which is part of the Center for Astrophysics (CfA) along with the Harvard College Observatory (HCO). ... This image is an artists rendering of the Oort cloud and the Kuiper Belt. ...