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Asteroid Pair
An asteroid pair, or (if more than one body) an asteroid cluster, are asteroids which at some point in the past had very small relative velocities, and are typically formed either by a collisional break-up of a parent body, or from binary asteroids which became gravitationally unbound and are now following similar but different orbits around the Sun. A possible example of a pair are the Trojan asteroids 1583 Antilochus and 3801 Thrasymedes. The proposer of that pair, Andrea Milani (mathematician), Andrea Milani, found five other potential asteroid clusters in the Greek camp, clustered around the asteroids 1437 Diomedes, 1647 Menelaus, 2456 Palamedes, 2797 Teucer and 4035 Thestor. The youngest asteroid pairs discovered include the main-belt asteroids P/2016 J1 (PanSTARRS), P/2016 J1-A/B (separated c. 2010) and / (separated c. 2003). The former pair is particularly remarkable for exhibiting active asteroid, comet-like activity due to water ice sublimation and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. Of the roughly one million known asteroids the greatest number are located between the orbits of Mars and Jupiter, approximately 2 to 4 AU from the Sun, in the main asteroid belt. Asteroids are generally classified to be of three types: C-type, M-type, and S-type. These were named after and are generally identified with carbonaceous, metallic, and silicaceous compositions, respectively. The size of asteroids varies greatly; the largest, Ceres, is almost across and qualifies as a dwarf planet. The total mass of all the asteroids combined is only 3% that of Earth's Moon. The majority of main belt asteroids follow slightly elliptical, stable orbits, revolving in the same direction as the Earth and taking from three to six years to comple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parent Body
In meteoritics, a parent body is the celestial body from which originates a meteorite or a class of meteorites. Identification The easiest way to correlate a meteorite with a parent body is when the parent body still exists. This is the case for Lunar and Martian meteorites. Samples from Lunar meteorites can be compared with samples from the Apollo program. Martian meteorites can be compared to analysis carried out by rovers (e.g. Curiosity). Meteorites can also be compared to spectral classes of asteroids. In order to identify the parent body of a class of meteorites, scientists compare their albedo and spectra with other known bodies. These studies show that some meteorite classes are closely related to some asteroids. The HED meteorites for example are correlated with 4 Vesta.Gunter Faure, Teresa M. Mensing. ''Introduction to Planetary Science: The Geological Perspective''Page 175 Another, perhaps most useful way to classify meteorites by parent bodies is by grouping t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Asteroid
A binary asteroid is a system of two asteroids orbiting their common barycenter. The binary nature of 243 Ida was discovered when the Galileo spacecraft flew by the asteroid in 1993. Since then numerous binary asteroids and several triple asteroids have been detected. The mass ratio of the two components – called the "primary" and "secondary" of a binary system – is an important characteristic. Most binary asteroids have a large mass ratio, i.e. a relatively small satellite in orbit around the main component. Systems with a small minor-planet moon – also called "companion" or simply "satellite" – include 87 Sylvia, 107 Camilla, 45 Eugenia, 121 Hermione, 130 Elektra, 22 Kalliope, 283 Emma, 379 Huenna, 243 Ida and 4337 Arecibo (in order of decreasing primary size). Some binary systems have a mass ratio near unity, i.e., two components of similar mass. They include 90 Antiope, , and 69230 Hermes, with average compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trojan Asteroid
In astronomy, a trojan is a small celestial body (mostly asteroids) that shares the orbit of a larger body, remaining in a stable orbit approximately 60° ahead of or behind the main body near one of its Lagrangian points and . Trojans can share the orbits of planets or of large moons. Trojans are one type of co-orbital object. In this arrangement, a star and a planet orbit about their common barycenter, which is close to the center of the star because it is usually much more massive than the orbiting planet. In turn, a much smaller mass than both the star and the planet, located at one of the Lagrangian points of the star–planet system, is subject to a combined gravitational force that acts through this barycenter. Hence the smallest object orbits around the barycenter with the same orbital period as the planet, and the arrangement can remain stable over time. In the Solar System, most known trojans share the orbit of Jupiter. They are divided into the Greek camp at (ah ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1583 Antilochus
1583 Antilochus is a large Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 19 September 1950, by Belgian astronomer Sylvain Arend at Uccle Observatory in Belgium, and later named after the hero Antilochus from Greek mythology. The dark D-type asteroid belongs to the 20 largest Jupiter trojans and has a rotation period of 15.9 hours. It forms an asteroid pair with 3801 Thrasymedes. Classification and orbit ''Antilochus'' is a dark Jovian asteroid orbiting in the leading Greek camp at Jupiter's Lagrangian point, 60 ° ahead of its orbit in a 1:1 resonance . It is also a non-family asteroid in the Jovian background population. It orbits the Sun at a distance of 4.9–5.4 AU once every 11 years and 7 months (4,244 days; semi-major axis of 5.13 AU). Its orbit has an eccentricity of 0.05 and an inclination of 29 ° with respect to the ecliptic. The asteroid was first observed as ' at Heidelberg Observatory in November 1926. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3801 Thrasymedes
3801 Thrasymedes is a mid-sized Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 6 November 1985, by astronomers with the Spacewatch survey at the Kitt Peak National Observatory in Arizona, United States. The dark Jovian asteroid has a rotation period of 20.3 hours and forms an asteroid pair with 1583 Antilochus. It was named after Thrasymedes from Greek mythology. Orbit and classification ''Thrasymedes'' is a dark Jovian asteroid in a 1:1 orbital resonance with Jupiter. It is located in the leading Greek camp at the Gas Giant's Lagrangian point, 60 ° ahead on its orbit . It is also a non-family asteroid of the Jovian background population. It orbits the Sun at a distance of 5.2–5.4 AU once every 12 years and 3 months (4,486 days; semi-major axis of 5.32 AU). Its orbit has an eccentricity of 0.02 and an inclination of 28 ° with respect to the ecliptic. The body's observation arc begins with a precovery taken at Paloma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrea Milani (mathematician)
Andrea Milani Comparetti (Florence, 19 June 1948 – Pisa, 28 November 2018) was an Italian mathematician and astronomer, based at the University of Pisa. Biography Andrea Milani Comparetti was born in Florence, in 1948. His father, Adriano Milani Comparetti, was a pioneer in child neuro-psychiatric rehabilitation and his uncle was Don Lorenzo Milani. In 1970 he graduated in Mathematics at the University of Milan and later he studied at the Scuola Normale Superiore di Pisa. He then became a Full Professor of Mathematical Physics at the Department of Mathematics of the University of Pisa. He died on November 28, 2018, for a sudden illness, causing a deep loss in the scientific community. Career His areas of research included the N-body problem, the stability of the Solar System, asteroid dynamics, asteroid families, satellite geodesy, planetary exploration, orbit determination and asteroid impact risk assessment. In his brilliant career he pioneered most of the previous topics. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Camp
This is a list of Jupiter trojans that lie in the Greek camp, an elongated curved region around the leading Lagrangian point (), 60 ° ahead of Jupiter in its orbit. All the asteroids at Jupiter's 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" () Lagrangian point. In 2018, at its 30th General Assembly in Vienna, the International Astronomical Union amended this naming convention, allowing for Jupiter trojans with '' 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. Trojans in the Greek and Trojan camp are discovered mainly in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1437 Diomedes
1437 Diomedes is a large Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 3 August 1937, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The dark D/P-type asteroid belongs to the largest Jupiter trojans and has a notably elongated shape and a longer than average rotation period of 24.49 hours. ''Diomedes'' was the first Jupiter trojan successfully observed during an occultation event of star. It was named after the hero Diomedes from Greek mythology. Orbit and classification ''Diomedes'' is a dark Jovian asteroid orbiting in the leading Greek camp at Jupiter's Lagrangian point, 60 ° ahead of the Gas Giant's orbit in a 1:1 resonance . It is also a non-family asteroid in the Jovian background population. Jupiter trojans are thought to have been captured into their orbits during or shortly after the early stages of the formation of the Solar System. More than 4,500 Jupiter trojans in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1647 Menelaus
1647 Menelaus is a mid-sized Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 23 June 1957 by American astronomer Seth Nicholson at the Palomar Observatory in California, and later named after the Spartan King Menelaus from Greek mythology. The dark asteroid has a rotation period of 17.7 hours. It is the principal body of the proposed Menelaus cluster, which encompasses several, mostly tentative Jovian asteroid families. Orbit and classification ''Menelaus'' is a dark Jovian asteroid in a 1:1 orbital resonance with Jupiter. It is located in the leading Greek camp at the Gas Giant's Lagrangian point, 60 ° ahead on its orbit . Since the discovery of the first Jupiter trojan, 588 Achilles, by astronomer Max Wolf in 1906, more than 7000 Jovian asteroids have already been discovered. It orbits the Sun at a distance of 5.1–5.3 AU once every 11 years and 11 months (4,347 days; semi-major axis of 5.21 AU). Its orbit has an eccent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2456 Palamedes
2456 Palamedes is a large Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 30 January 1966, by astronomers at the Purple Mountain Observatory in Nanking, China. The assumed C-type asteroid has a rotation period of 7.24 hours and belongs to the 50 largest Jupiter trojans. It was named after Palamedes from Greek mythology. Orbit and classification ''Palamedes'' is a dark Jovian asteroid orbiting in the leading Greek camp at Jupiter's Lagrangian point, 60 ° ahead of the Gas Giant's orbit in a 1:1 resonance ''(see Trojans in astronomy)''. It is also a non-family asteroid in the Jovian background population. It orbits the Sun at a distance of 4.7–5.5 AU once every 11 years and 7 months (4,244 days; semi-major axis of 5.13 AU). Its orbit has an eccentricity of 0.07 and an inclination of 14 ° with respect to the ecliptic. The body's observation arc begins with a precovery taken at Palomar Observatory in February 1953, nearly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2797 Teucer
2797 Teucer is a large Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 4 June 1981, by American astronomer Edward Bowell at the Anderson Mesa Station near Flagstaff, Arizona, in the United States. The dark D-type asteroid belongs to the 20 largest Jupiter trojans and has a rotation period of 10.15 hours. It was named after the Greek hero and great archer, Teucer. Orbit and classification ''Teucer'' is a dark Jovian asteroid orbiting in the leading Greek camp at Jupiter's Lagrangian point, 60 ° ahead of its orbit in a 1:1 resonance . It is also a non-family asteroid in the Jovian background population. It orbits the Sun at a distance of 4.7–5.6 AU once every 11 years and 6 months (4,213 days; semi-major axis of 5.1 AU). Its orbit has an eccentricity of 0.09 and an inclination of 22 ° with respect to the ecliptic. The body's observation arc begins with its first observation as ' at Turku Observatory in December 1940, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
