Jupiter trojan in the context of 2010 TK7

The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids or minor planets. The identified objects are of many sizes, but much smaller than planets, and, on average, are about one million kilometers (or six hundred thousand miles) apart. This asteroid belt is also called the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System.

The asteroid belt is the smallest and innermost circumstellar disc in the Solar System. Classes of small Solar System bodies in other regions are the near-Earth objects, the centaurs, the Kuiper belt objects, the scattered disc objects, the sednoids, and the Oort cloud objects. About 60% of the main belt mass is contained in the four largest asteroids: Ceres, Vesta, Pallas, and Hygiea. The total mass of the asteroid belt is estimated to be 3% that of the Moon.

According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term minor planet, but that year's meeting reclassified minor planets and comets into dwarf planets and small Solar System bodies (SSSBs). In contrast to the eight official planets of the Solar System, all minor planets fail to clear their orbital neighborhood.

Minor planets include asteroids (near-Earth objects, Earth trojans, Mars trojans, Mars-crossers, main-belt asteroids and Jupiter trojans), as well as distant minor planets (Uranus trojans, Neptune trojans, centaurs and trans-Neptunian objects), most of which reside in the Kuiper belt and the scattered disc. As of October 2025, there are 1,472,966 known objects, divided into 875,150 numbered, with only one of them recognized as a dwarf planet (secured discoveries) and 597,816 unnumbered minor planets, with only five of those officially recognized as a dwarf planet.

The Kuiper belt (/ˈkaɪpər/ ) is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times as wide and 20–200 times as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed. While many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia, and water. The Kuiper belt is home to most of the objects that astronomers generally accept as dwarf planets: Orcus, Pluto, Haumea, Quaoar, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may have originated in the region.

The Kuiper belt is named in honor of the Dutch astronomer Gerard Kuiper, who conjectured the existence of a version of the belt in 1951. There were researchers before and after him who proposed similar hypoetheses, such as Kenneth Edgeworth in the 1930s. The most direct prediction of the belt was by astronomer Julio Ángel Fernández, who published a paper in 1980 suggesting the existence of a comet belt beyond Neptune which could serve as a source for short-period comets.

In planetary astronomy, a centaur is a small Solar System body that orbits the Sun between Jupiter and Neptune and crosses the orbits of one or more of the giant planets. Centaurs generally have unstable orbits because of this; almost all their orbits have dynamic lifetimes of only a few million years, but there is one known centaur, 514107 Kaʻepaokaʻāwela, which may be in a stable (though retrograde) orbit. Centaurs typically exhibit the characteristics of both asteroids and comets. They are named after the mythological centaurs that were a mixture of horse and human. Observational bias toward large objects makes determination of the total centaur population difficult. Estimates for the number of centaurs in the Solar System more than 1 km in diameter range from as low as 44,000 to more than 10,000,000.

The first centaur to be discovered, under the definition of the Jet Propulsion Laboratory and the one used here, was 944 Hidalgo in 1920. However, they were not recognized as a distinct population until the discovery of 2060 Chiron in 1977. The largest confirmed centaur is 10199 Chariklo, which at 250 kilometers in diameter is as big as a mid-sized main-belt asteroid, and is known to have a system of rings. It was discovered in 1997.

617 Patroclus (/pəˈtroʊkləs/ pə-TROH-kləs) is a large binary Jupiter trojan asteroid. It is a dark D-type asteroid and a slow rotator, due to the 103-hour orbital period of its two components. It is one of five Jupiter trojan asteroids targeted by the Lucy space probe, and is scheduled for a flyby in 2033.

Patroclus was discovered on 17 October 1906, by astronomer August Kopff at the Heidelberg Observatory in Germany, and was named after Patroclus in Greek mythology. It was the second trojan to be discovered and the only member of the Trojan camp named after a Greek figure, as the convention of naming one 'camp' after Greek figures of the Trojan War and the other after Trojan figures had not yet been established.

An Earth trojan is an asteroid that orbits the Sun in the vicinity of the Earth–Sun Lagrange points L₄ (leading 60°) or L₅ (trailing 60°), thus having an orbit similar to Earth's. Only two Earth trojans have so far been discovered. The name "trojan" was first used in 1906 for the Jupiter trojans, the asteroids that were observed near the Lagrangian points of Jupiter's orbit.

A distant minor planet, or distant object, is any minor planet found beyond Jupiter in the outer Solar System that is not commonly thought of as an "asteroid". The umbrella term is used by IAU's Minor Planet Center (MPC), which is responsible for the identification, designation and orbit computation of these objects. As of January 2025, the MPC maintains 6101 distant objects in its data base.

Most distant minor planets are trans-Neptunian objects and centaurs, while relatively few are damocloids, Neptune trojans or Uranus trojans. All distant objects have a semi-major axis (average distance from the Sun) greater than 6 AU. This threshold, which is just beyond the orbit of Jupiter (5.2 AU), ensures that the vast majority of "true asteroids" – such as the near-Earth, Mars-crosser, main-belt and Jupiter trojan populations – are excluded from the distant minor planets.

Neptune trojans are bodies that orbit the Sun near one of the stable Lagrangian points of Neptune, similar to the trojans of other planets. They therefore have approximately the same orbital period as Neptune and follow roughly the same orbital path. Thirty-one Neptune trojans are currently known, of which 27 orbit near the Sun–Neptune L₄ Lagrangian point 60° ahead of Neptune and four orbit near Neptune's L₅ region 60° behind Neptune. The Neptune trojans are termed 'trojans' by analogy with the Jupiter trojans.

The discovery of 2005 TN53 in a high-inclination (>25°) orbit was significant, because it suggested a "thick" cloud of trojans (Jupiter trojans have inclinations up to 40°), which is indicative of freeze-in capture instead of in situ or collisional formation. It is suspected that large (radius ≈ 100 km) Neptune trojans could outnumber Jupiter trojans of that size by an order of magnitude.

The following is a list of unnumbered minor planets in chronological order of their principal provisional designation. Contrary to their numbered counterparts, unnumbered minor planets have a poorly determined orbit due to insufficient observational data. This also includes lost minor planets which have not been observed for many years, or even decades. As of August 2023, the Minor Planet Center (MPC) accounts for 676,755 unnumbered minor planets which represent 52% of the overall minor planet population. Unnumbered minor planets can be further divided into 129,103 single-opposition objects with short observation arcs, prone to mismatch and loss, and 547,652 objects that have been observed multiple times during opposition, when astrometric conditions are most favorable. The JPL Small-Body Database gives a running total of 676,786 unnumbered minor planets.

The tables below contain 115 objects with a principal designation assigned between 1927 and 1994. Additional partial lists cover the period from 1995 to 2004. Unnumbered minor planets detected after 2004 are not listed due to their large number. The orbital uncertainty parameter (U) ranges from low ("0") to very high ("9"). For some single-opposition objects no numeric uncertainty is given ("–"), with "E" indicating an estimated, rather than determined orbital eccentricity. Furthermore, a color code is used to indicate a body's basic dynamical classification, with additional information given in columns "class" and "description and notes" (especially for near-Earth objects, Jupiter trojans and distant objects). If available, mean diameters are taken from the latest NEOWISE publication, or, if not available, estimated based on an object's absolute magnitude and displayed in italics.

D-type asteroids have a very low albedo and a featureless reddish spectrum. It has been suggested that they have a composition of organic-rich silicates, carbon and anhydrous silicates, possibly with water ice in their interiors. D-type asteroids are found in the outer asteroid belt and beyond; examples are 152 Atala, 944 Hidalgo and most Jupiter trojans. It has been suggested that the Tagish Lake meteorite was a fragment from a D-type asteroid, and that the Martian moon Phobos is closely related.

The Nice model suggests that D-type asteroids may have originated in the Kuiper belt. 46 D-type asteroids are known, including: 3552 Don Quixote, 944 Hidalgo, 624 Hektor, and 10199 Chariklo.

This is a list of notable minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). As of 22 October 2025, the discovery of over 800,000 numbered minor planets are credited to 2,186 astronomers, observatories, telescopes or surveys.

The following is a list of Solar System objects by orbit, ordered by increasing distance from the Sun. Most named objects in this list have a diameter of 500 km or more.

• The Sun, a spectral class G2V main-sequence star
• The inner Solar System and the terrestrial planets
  • Mercury
    • Mercury-crossing minor planets
  • Venus
    • Venus-crossing minor planets
      • Zoozve, Venus' quasi-satellite
  • Earth
    • Moon
    • Near-Earth asteroids
      • 2021 PH27
      • Apophis
      • Eros
    • Earth trojans (2010 TK7)
    • Earth-crosser asteroids
      • Earth's quasi-satellites
  • Mars
    • Deimos
    • Phobos
    • Mars trojans
    • Mars-crossing minor planets
  • Asteroids in the asteroid belt, between the orbits of Mars and Jupiter
    • Ceres, a dwarf planet
    • Vesta
    • Pallas
    • Hygiea
    • Europa (asteroid)
    • Davida
    • Sylvia
    • Asteroids number in the hundreds of thousands. For longer lists, see list of exceptional asteroids, list of asteroids, or list of Solar System objects by size.
      • Asteroid moons
  • A number of smaller groups distinct from the asteroid belt
• The outer Solar System with the giant planets, their satellites, trojan asteroids and some minor planets
  • Jupiter
    • Rings of Jupiter
    • Complete list of Jupiter's natural satellites
      • Galilean moons
        • Io
        • Europa (moon)
        • Ganymede
        • Callisto
    • Jupiter trojans
    • Jupiter-crossing minor planets
  • Saturn
    • Rings of Saturn
    • Complete list of Saturn's natural satellites
      • Mimas
      • Enceladus
      • Tethys (trojans: Telesto and Calypso)
      • Dione (trojans: Helene and Polydeuces)
      • Rhea
        • Rings of Rhea (largely disproven)
      • Titan
      • Hyperion
      • Iapetus
      • Phoebe
      • Shepherd moons
    • Saturn-crossing minor planets
  • Uranus
    • Rings of Uranus
    • Complete list of Uranus's natural satellites
      • Miranda
      • Ariel
      • Umbriel
      • Titania
      • Oberon
    • Uranus trojan (2011 QF99)
    • Uranus-crossing minor planets
  • Neptune
    • Rings of Neptune
    • Complete list of Neptune's natural satellites
      • Proteus
      • Triton
      • Nereid
    • Neptune trojans
    • Neptune-crossing minor planets
  • Non-trojan minor planets
    • Centaurs
      • Chiron
      • Chariklo
    • Damocloids
  • Trans-Neptunian objects (beyond the orbit of Neptune)
    • Kuiper-belt objects (KBOs)
      • Plutinos
        • Orcus, a dwarf planet
          • Vanth
        • Pluto, a dwarf planet
          • Complete list of Pluto's natural satellites
            • Charon
        • Ixion
        • Achlys
      • Twotinos
      • Cubewanos (classical objects)
        • Haumea, a dwarf planet
          • Namaka
          • Hiʻiaka
        • Quaoar, a dwarf planet
          • Weywot
        • Makemake, a dwarf planet
          • S/2015 (136472) 1
        • Máni
        • Salacia
          • Actaea
        • Aya
        • Varda
          • Ilmarë
        • Varuna
        • Ritona
        • Arrokoth
    • Scattered-disc objects
      • Gonggong, a dwarf planet
        • Xiangliu
      • Eris, a dwarf planet
        • Dysnomia
      • Chiminigagua
      • (84522) 2002 TC302
      • (87269) 2000 OO67
      • 2015 TH367/V774104
    • Detached objects
      • (612911) 2004 XR190
      • 2012 VP113 (possibly inner Oort cloud)
      • Sedna, a dwarf planet (possibly inner Oort cloud)
    • Oort cloud (hypothetical)
      • Hills cloud/inner Oort cloud
      • Outer Oort cloud

In astronomy, the Nice (/ˈniːs/) model is a scenario for the dynamical evolution of the Solar System. It is named for the location of the Côte d'Azur Observatory—where it was initially developed in 2005—in Nice, France. It proposes the migration of the giant planets from an initial compact configuration into their present positions, long after the dissipation of the initial protoplanetary disk. In this way, it differs from earlier models of the Solar System's formation. This planetary migration is used in dynamical simulations of the Solar System to explain historical events including the Late Heavy Bombardment of the inner Solar System, the formation of the Oort cloud, and the existence of populations of small Solar System bodies such as the Kuiper belt, the Neptune and Jupiter trojans, and the numerous resonant trans-Neptunian objects dominated by Neptune.

The Hilda asteroids (adj. Hildian) are a dynamical group of more than 6,000 asteroids located beyond the asteroid belt but within Jupiter's orbit, in a 3:2 orbital resonance with Jupiter; that is, while Jupiter orbits twice, the Hildas orbit three times. The namesake is the asteroid 153 Hilda.

Hildas move in their elliptical orbits in such a fashion that they arrive closest to Jupiter's orbit (i.e. at their aphelion) just when either one of Jupiter's L₅, L₄ or L₃ Lagrange points arrives there. On their next orbit their aphelion will synchronize with the next Lagrange point in the L₅–L₄–L₃ sequence. Since L₅, L₄ and L₃ are 120° apart, by the time a Hilda completes an orbit, Jupiter will have completed 360° − 120° or two-thirds of its own orbit. A Hilda's orbit has a semi-major axis between 3.7 and 4.2 AU (the average over a long time span is 3.97), an eccentricity less than 0.3, and an inclination less than 20°. Two collisional families exist within the Hilda group: the Hilda family and the Schubart family. The namesake for the latter family is 1911 Schubart.

This is a list of Jupiter trojans that lie in the Greek camp, an elongated curved region around the leading Lagrangian point (L₄), 60° ahead of Jupiter in its orbit.

All the asteroids at Jupiter's L₄ point have names corresponding to participants on the Greek side of the Trojan War, except for 624 Hektor, which was named before this naming convention was instituted. Correspondingly, 617 Patroclus is a Greek-named asteroid at the "Trojan" (L₅) Lagrangian point. In 2018, at its 30th General Assembly in Vienna, the International Astronomical Union amended this naming convention, allowing Jupiter trojans with an H larger than 12 (that is, a mean diameter smaller than approximately 22 kilometers, for an assumed albedo of 0.057) to be named after Olympic athletes, as the number of known Jupiter trojans, currently more than 10,000, far exceeds the number of available names of heroes from the Trojan War in Greek mythology.