"environmental mismanagement. A further extension is from the past of the existing asteroids to the possible future destruction of Earth or other planets and their rendering into new asteroids. The earliest explicit references to asteroids date from the late nineteenth century: Although the asteroids are commonly dealt with ""en masse"", a few belt asteroids have become known well enough to be mentioned in fictional treatments. Dwarf planet Ceres is the largest and first discovered planetoid of the main-belt asteroids. After Ceres, Asteroid 433 Eros is perhaps the most-commonly mentioned asteroid, probably because it is one of the largest near-Earth asteroids."
"to rocks just 1 meter across. The three largest are very much like miniature planets: they are roughly spherical, have at least partly differentiated interiors, and are thought to be surviving protoplanets. The vast majority, however, are much smaller and are irregularly shaped; they are thought to be either surviving planetesimals or fragments of larger bodies. The dwarf planet Ceres is by far the largest asteroid, with a diameter of . The next largest are 4 Vesta and 2 Pallas, both with diameters of just over . Vesta is the only main-belt asteroid that can, on occasion, be visible to"
"were named after and are generally identified with carbon-rich, metallic, and silicate (stony) compositions, respectively. The sizes of asteroids varies greatly; the largest, Ceres, is almost across. Asteroids are differentiated from comets and meteoroids. In the case of comets, the difference is one of composition: while asteroids are mainly composed of mineral and rock, comets are primarily composed of dust and ice. Furthermore, asteroids formed closer to the sun, preventing the development of cometary ice. The difference between asteroids and meteoroids is mainly one of size: meteoroids have a diameter of less than one meter, whereas asteroids have a diameter"
"were instead classified as dwarf planets. Ceres is the largest object in the asteroid belt. It is sometimes assumed that Ceres has been ""re""classified as a dwarf planet, and that it is therefore no longer considered an asteroid. For example, a news update at Space.com spoke of ""Pallas, the largest asteroid, and Ceres, the dwarf planet formerly classified as an asteroid"", whereas an IAU question-and-answer posting states, ""Ceres is (or now we can say it was) the largest asteroid"", though it then speaks of ""other asteroids"" crossing Ceres' path and otherwise implies that Ceres is still considered an asteroid. The"
"65 Cybele Cybele ( minor planet designation: 65 Cybele) is one of the largest asteroids in the Solar System and is located in the outer asteroid belt. It gives its name to the Cybele group of asteroids that orbit outward from the Sun from the 2:1 orbital resonance with Jupiter. The X-type asteroid has a relatively short rotation period of 6.0814 hours. It was discovered by Wilhelm Tempel in 1861, and named after Cybele, the earth goddess. ""Cybele"" was discovered on 8 March 1861, by German astronomer Wilhelm Tempel from the Marseilles Observatory in southeastern France. A minor controversy arose"
"15 Eunomia Eunomia (minor planet designation 15 Eunomia) is a very large asteroid in the inner asteroid belt. It is the largest of the stony (S-type) asteroids, and somewhere between the 8th- and 12th-largest main-belt asteroid overall (uncertainty in diameters causes uncertainty in its ranking). It is the largest Eunomian asteroid, and is estimated to contain 1% of the mass of the asteroid belt. Eunomia was discovered by Annibale de Gasparis on July 29, 1851, and named after Eunomia, one of the Horae (Hours), a personification of order and law in Greek mythology. As the largest S-type asteroid (with 3"
"fragments dominates and prevents small pieces from falling inwards and filling up the voids. All the largest asteroids (1 Ceres, 2 Pallas, 4 Vesta, 10 Hygiea, 704 Interamnia) are solid objects without any macroscopic internal porosity. This may be because they have been large enough to withstand all impacts, and have never been shattered. Alternatively, Ceres and some few other of the largest asteroids may be massive enough that, even if they were shattered but not dispersed, their gravity would collapse most voids upon recoalescing. Vesta, at least, has withstood intact one major impact since its formation and shows signs"
"perhaps partially differentiated. Pallas is the parent body of the Palladian family of asteroids. Hygiea is the largest carbonaceous asteroid and, unlike the other largest asteroids, lies relatively close to the plane of the ecliptic. It is the largest member and presumed parent body of the Hygiean family of asteroids. Measurements of the rotation rates of large asteroids in the asteroid belt show that there is an upper limit. No asteroid with a diameter larger than 100 meters has a rotation period smaller than 2.2 hours. For asteroids rotating faster than approximately this rate, the inertial force at the surface"
"the largest C-type asteroids require a small telescope. The potentially brightest C-type asteroid is 324 Bamberga, but that object's very high eccentricity means it rarely reaches its maximum magnitude. Their spectra contain moderately strong ultraviolet absorption at wavelengths below about 0.4 μm to 0.5 μm, while at longer wavelengths they are largely featureless but slightly reddish. The so-called ""water"" absorption feature of around 3 μm, which can be an indication of water content in minerals, is also present. The largest unequivocally C-type asteroid is 10 Hygiea, although the SMASS classification places the largest asteroid, 1 Ceres, here as well, because"
"Ceres (dwarf planet) Ceres (; minor-planet designation: 1 Ceres) is the largest object in the asteroid belt that lies between the orbits of Mars and Jupiter, slightly closer to Mars' orbit. With a diameter of , Ceres is the largest of the minor planets, and the only dwarf planet, inside Neptune's orbit. It is the 33rd-largest known body in the Solar System. Ceres is composed of rock and ice and is estimated to comprise approximately one-third of the mass of the entire asteroid belt. Ceres is the only object in the asteroid belt known to be rounded by its own"
"be found from the object's magnitude because an assumption must be made for its albedo which is also not usually known for certain. The NASA near-Earth object program uses an assumed albedo of 0.14 for this purpose. In May 2016, the asteroid size estimates arising from the Wide-field Infrared Survey Explorer and NEOWISE missions have been questioned. Although the early original criticism had not undergone peer review, a more recent peer-reviewed study was subsequently published. With a mean-diameter of approximately 7 kilometers, the Apollo asteroid is likely the largest known potentially hazardous object, despite its fainter absolute magnitude of 15.2,"
"Asteroid belt The asteroid belt is the circumstellar disc in the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets. The asteroid belt is also termed the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System such as near-Earth asteroids and trojan asteroids. About half the mass of the belt is contained in the four largest asteroids: Ceres, Vesta, Pallas, and Hygiea. The total mass of the asteroid belt is approximately 4% that of the"
"period in orbit and at the surface. Asteroid belt The asteroid belt is the circumstellar disc in the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets. The asteroid belt is also termed the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System such as near-Earth asteroids and trojan asteroids. About half the mass of the belt is contained in the four largest asteroids: Ceres, Vesta, Pallas, and Hygiea. The total mass of the asteroid"
"with flying glass from broken windows, was an Apollo class asteroid. The largest known Apollo asteroid is 1866 Sisyphus, with a diameter of about 8.5 km. Examples of known Apollo asteroids include: Apollo asteroid The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, discovered by German astronomer Karl Reinmuth in the 1930s. They are Earth crossing asteroids that have an orbital semi-major axis greater than that of the Earth (> 1 AU) but perihelion distances less than the Earth's aphelion distance (q < 1.017 AU). The closer their semi-major axis is to Earth's, the less eccentricity"
"29 Amphitrite Amphitrite ( ; minor planet designation: 29 Amphridite) is one of the largest S-type asteroids, approximately in diameter, and probably third largest after Eunomia and Juno, although Iris and Herculina are similar in size. Amphitrite was discovered by Albert Marth on March 1, 1854, at the private South Villa Observatory, in Regent's Park, London. It was Marth's only asteroid discovery. Its name was chosen by George Bishop, the owner of the observatory, who named it after Amphitrite, a sea goddess in Greek mythology. Amphirite's orbit is less eccentric and inclined than those of its larger cousins; indeed, it"
"48 Doris Doris (minor planet designation: 47 Doris) is one of the largest main belt asteroids. It was discovered on 19 September 1857 by Hermann Goldschmidt from his balcony in Paris. To find a name for the object, Jacques Babinet of the Academy of Sciences created a shortlist and asked the geologist Élie de Beaumont to make the selection. De Beaumont chose Doris, after an Oceanid in Greek mythology. Since Doris was discovered on the same night as 49 Pales, de Deaumont suggested naming the two ""The Twins"". An occultation on March 19, 1981, suggested a diameter of 219±25 km."
"S-type asteroid S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. Approximately 17% of asteroids are of this type, making it the second most common after the carbonaceous C-type. S-types asteroids, with an astronomical albedo of typically 0.20, are moderately bright and consist mainly of iron- and magnesium-silicates. They are dominant in the inner part of the asteroid belt within 2.2 AU, common in the central belt within about 3 AU, but become rare farther out. The largest is 15 Eunomia (about 330 km wide across its longest"
"quadrangles. They are named after the first craters whose names the IAU approved in July 2015. The map image(s) were taken by the ""Dawn"" space probe. Ceres (dwarf planet) Ceres (; minor-planet designation: 1 Ceres) is the largest object in the asteroid belt that lies between the orbits of Mars and Jupiter, slightly closer to Mars' orbit. With a diameter of , Ceres is the largest of the minor planets, and the only dwarf planet, inside Neptune's orbit. It is the 33rd-largest known body in the Solar System. Ceres is composed of rock and ice and is estimated to comprise"
"add another 3% to the total mass. The number of asteroids then increases rapidly as their individual masses decrease. The number of asteroids decreases markedly with size. Although this generally follows a power law, there are 'bumps' at and , where more asteroids than expected from a logarithmic distribution are found. Although their location in the asteroid belt excludes them from planet status, the three largest objects, Ceres, Vesta, and Pallas, are intact protoplanets that share many characteristics common to planets, and are atypical compared to the majority of ""potato""-shaped asteroids. The fourth largest asteroid, Hygiea, has an undifferentiated interior,"
"1388 Aphrodite 1388 Aphrodite, provisional designation , is an asteroid of the Eos family from the outer regions of the asteroid belt, approximately in diameter. It was discovered on 24 September 1935, by Belgian astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle. The likely elongated K-type asteroid has a rotation period of 11.9 hours. It was named after the Greek goddess Aphrodite from Greek mythology. ""Aphrodite"" is a core member of the Eos family (), the largest asteroid family in the outer main belt consisting of nearly 10,000 asteroids. It orbits the Sun at a distance of"
"despite being one of the largest asteroids. It is a C-type asteroid with a primitive surface. Its orbit, however, is quite unusual and bears a considerable resemblance to that of 2 Pallas in its high inclination and eccentricity. Whereas Pallas and Eris—the only larger bodies with comparably tilted orbits—have nodes near perihelion and aphelion, Euphrosyne's perihelion lies at the northernmost point of its orbit. During a rare perihelic opposition Euphrosyne is very high in the sky from northern latitudes, but invisible from such countries as New Zealand and Chile. The mass estimate of Euphrosyne in Baer (2011) makes it apparently"
"24 Themis Themis ('; minor planet designation: 24 Themis) is one of the largest asteroids in the asteroid belt. It is also the largest member of the Themis family. It was discovered by Annibale de Gasparis on 5 April 1853. It is named after Themis, the personification of natural law and divine order in Greek mythology. Not to be confused with 269 Justitia, named for Justitia, Themis' Roman name. 24 Themis was discovered on 5 April 1853 by Annibale de Gasparis of Naples, though it was given its name by fellow Italian astronomer Angelo Secchi. The asteroid was named after"
"had their size directly measured. 2018 AH 2018 AH is a sub-kilometer asteroid, classified as near-Earth object of the Apollo group, approximately in diameter. It was first observed on 4 January 2018, by the Asteroid Terrestrial-impact Last Alert System (ATLAS) on Mauna Loa and quickly followed-up by many other surveys, with precovery observations found from Pan-STARRS and PTF from the day previous. It is the largest known asteroid to pass so close to Earth () since in 1971, and until in 2028, although it was only discovered two days after its closest approach on 2 January 2018, at 04:25 UTC."
"2018 AH 2018 AH is a sub-kilometer asteroid, classified as near-Earth object of the Apollo group, approximately in diameter. It was first observed on 4 January 2018, by the Asteroid Terrestrial-impact Last Alert System (ATLAS) on Mauna Loa and quickly followed-up by many other surveys, with precovery observations found from Pan-STARRS and PTF from the day previous. It is the largest known asteroid to pass so close to Earth () since in 1971, and until in 2028, although it was only discovered two days after its closest approach on 2 January 2018, at 04:25 UTC. The Tunguska asteroid was likely"
"1866 Sisyphus 1866 Sisyphus ( ), provisional designation , is a binary stony asteroid, near-Earth object and the largest member of the Apollo group, approximately 7 kilometers in diameter. It was discovered on 5 December 1972, by Swiss astronomer Paul Wild at Zimmerwald Observatory near Bern, Switzerland, and named after Sisyphus from Greek mythology. This S-type asteroid (composed of rocky silicates) orbits the Sun in the inner main-belt at a distance of 0.9–2.9 AU once every 2 years and 7 months (952 days). Its orbit has an eccentricity of 0.54 and an inclination of 41° with respect to the ecliptic."
"19848 Yeungchuchiu 19848 Yeungchuchiu, provisional designation , is a stony Eos asteroid from the outer region of the asteroid belt, approximately 12 kilometers in diameter. It was discovered on 2 October 2000 by Canadian amateur astronomer William Yeung at the Desert Beaver Observatory in Arizona, United States. It is the largest object found by the discoverer, just 1°.2 west of Jupiter, who named it after his father, Chu Chiu Yeung. ""Yeungchuchiu"" is a member of the Eos family, an orbital group of more than 4,000 asteroids, which are known for mostly being of stony composition. It orbits the Sun in"
"all have impact craters and tectonic surface features, such as rift valleys and volcanoes. The term ""inner planet"" should not be confused with ""inferior planet"", which designates those planets that are closer to the Sun than Earth is (i.e. Mercury and Venus). Asteroids except for the largest, Ceres, are classified as small Solar System bodies and are composed mainly of refractory rocky and metallic minerals, with some ice. They range from a few metres to hundreds of kilometres in size. Asteroids smaller than one meter are usually called meteoroids and micrometeoroids (grain-sized), depending on different, somewhat arbitrary definitions. The asteroid"
"impact. The largest is Saturnalia Fossa, approx. 39 km wide and > 400 km long. Veneneia Veneneia ( ) is the second-largest crater on asteroid 4 Vesta, at 52°S latitude. in diameter, it is 70% of the equatorial diameter of the asteroid, and one of the largest craters in the Solar System. It is at least 2 billion years old. However, it is overlain and partially obliterated by the even larger Rheasilvia. It was discovered by the ""Dawn"" spacecraft in 2011. It is named after ""Venēneia"", one of the founding vestal virgins. Vesta has a series of troughs in the"
"the time, asteroids were supposed to receive names from classical mythology, and several astronomers protested the choice. Tempel noted that if the second 'n' were removed, the complaints would be satisfied (referring to Angelia, a minor Greek deity). However, Valz's choice stayed. Angelina is an uncommon form of E-type asteroid; it is the third largest E-type after 44 Nysa and 55 Pandora, and has an exceptionally high albedo. As of 1991, it is thought to have an average radius of about . Back when asteroids were generally assumed to have low albedos, Angelina was thought to be the largest of"
"primitive composition of carbonaceous chondrite, is thought to be the largest undifferentiated asteroid. Most of the smaller asteroids are thought to be piles of rubble held together loosely by gravity, though the largest are probably solid. Some asteroids have moons or are co-orbiting binaries: Rubble piles, moons, binaries, and scattered asteroid families are thought to be the results of collisions that disrupted a parent asteroid, or, possibly, a planet. Asteroids contain traces of amino acids and other organic compounds, and some speculate that asteroid impacts may have seeded the early Earth with the chemicals necessary to initiate life, or may"
"its methodology itself, a more recent peer-reviewed study was subsequently published. As of May 2018 and mostly using the crude estimate from an absolute magnitude, 889 NEAs listed by CNEOS, including 155 PHAs, measure at least 1 km in diameter, and 8,148 known NEAs are larger than 140 m in diameter. The smallest known near-Earth asteroid is with an absolute magnitude of 33.2, corresponding to a diameter of about . The largest such object is 1036 Ganymed, with an absolute magnitude of 9.45 and a diameter of about . In 2000, NASA reduced its estimate of the number of existing"
"Mars gravity assist in 2023. 16 Psyche Psyche ( ; minor planet designation: 16 Psyche) is one of the ten most massive asteroids in the asteroid belt. It is over 200 km (120 mi) in diameter and contains a little less than 1% of the mass of the entire asteroid belt. It is thought to be the exposed iron core of a protoplanet. It is the most massive metallic M-type asteroid. Psyche was discovered by the Italian astronomer Annibale de Gasparis on 17 March 1852 from Naples and named after the Greek mythological figure Psyche. The first fifteen asteroids to"
"of 24 Themis. This can be explained by the presence of water ice. The asteroid may be covered in a layer of fine silicate dust mixed with small amounts of water-ice and organic solids. On August 24, 2008, ""Cybele"" occulted 2UCAC 24389317, a 12.7-magnitude star in the constellation Ophiuchus which showed a long axis of at least 294 km. On 11 October 2009, ""Cybele"" occulted a 13.4-magnitude star in the constellation Aquarius. 65 Cybele Cybele ( minor planet designation: 65 Cybele) is one of the largest asteroids in the Solar System and is located in the outer asteroid belt. It"