Earth-crossing Asteroid
An Earth-crosser is a near-Earth asteroid whose orbit crosses that of Earth as observed from the ecliptic pole of Earth's orbit. The known numbered Earth-crossers are listed here. Those Earth-crossers whose semi-major axes are smaller than Earth's are Aten asteroids; the remaining ones are Apollo asteroids. ''(See also the Amor asteroids.)'' An asteroid with an Earth-crossing orbit is not necessarily in danger of colliding with Earth. The orbit of an Earth-crossing asteroid may not even intersect with that of Earth. This apparent contradiction arises because many asteroids have highly inclined orbits, so although they may have a perihelion less than that of Earth, their paths can never cross. An asteroid for which there is some possibility of a collision with Earth at a future date and which is above a certain size is classified as a potentially hazardous asteroid (PHA). Specifically, an asteroid is a PHA if its Earth minimum orbital intersection distance (MOID) is <0.05 [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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99942 Apophis
99942 Apophis is a near-Earth asteroid and potentially hazardous asteroid with a diameter of that caused a brief period of concern in December 2004 when initial observations indicated a probability up to 2.7% that it would hit Earth on April 13, 2029. Additional observations provided improved predictions that eliminated the possibility of an impact on Earth in 2029. Until 2006, a small probability nevertheless remained that, during its 2029 close encounter with Earth, Apophis would pass through a gravitational keyhole of no more than about in diameter, which would have set up a future impact exactly seven years later on April 13, 2036. This possibility kept it at Level 1 on the Torino impact hazard scale until August 2006, when the probability that Apophis would pass through the keyhole was determined to be very small and Apophis' rating on the Torino scale was lowered to zero. By 2008, the keyhole had been determined to be less than 1 km wide. During the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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2063 Bacchus
2063 Bacchus, provisional designation , is a stony asteroid and near-Earth object of the Apollo group, approximately 1 kilometer in diameter. The contact binary was discovered on 24 April 1977, by American astronomer Charles Kowal at the Palomar Observatory in California, United States. It was named after Bacchus from Roman mythology. Orbit and classification ''Bacchus'' orbits the Sun at a distance of 0.7–1.5 AU once every 1 years and 1 month (409 days). Its orbit has an eccentricity of 0.35 and an inclination of 9 ° with respect to the ecliptic. The asteroid's observation arc begins with its official discovery observation at Palomar. Due to its eccentric orbit, it is also a Venus-crosser. Approaches ''Bacchus'' has an ''Earth minimum orbital intersection distance'' of , which corresponds to 26.4 lunar distances. On 31 March 1996, it passed from Earth. Physical characteristics In the SMASS classification, ''Bacchus'' is a Sq-type, that transitions from the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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2062 Aten
2062 Aten , provisional designation , is a stony sub-kilometer asteroid and namesake of the Aten asteroids, a subgroup of near-Earth objects. The asteroid was named after Aten from Egyptian mythology. It was discovered on 7 January 1976, at the Palomar Observatory by American astronomer Eleanor Helin, who was the principal scientist for the NEAT project until her retirement in 2002. The S-type asteroid measures approximately 900 meters in diameter, has a longer-than average rotation period of 44.77 hours, and approaches the orbit Earth to 44.1 lunar distances. Orbit and classification ''Aten'' orbits the Sun at a distance of 0.8–1.1 AU once every 11 months (347 days). Its orbit has an eccentricity of 0.18 and an inclination of 19 ° with respect to the ecliptic. A first precovery was taken at the discovering observatory in December 1955, extending the body's observation arc by more than 20 years prior to its official discovery observation. Namesake of the Aten group ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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2016 NL56
(also written 2016 NL56) is a near-Earth object (NEO) and a potentially hazardous object (PHA), meaning that it has an orbit that can make close approaches to the Earth and large enough to cause significant regional damage in the event of impact. It is an Apollo asteroid, meaning that it is an Earth-crossing asteroid that has an orbit larger than the orbit of the Earth. It was first observed on 12 July 2016, when the asteroid was more than 1 AU from Earth and had a solar elongation of 163 degrees. This asteroid had been a lost asteroid until its rediscovery as, and identification with , in July 2021. With additional observations recovered dating back as far as August 2001, the object's previously short observation arc of 2.8 days has been extended to almost 20 years, and its roughly calculated orbit has become secure with an uncertainty parameter of 1. It orbits the Sun at a distance of 0.6–2.2 AU once every 20 months (609 days; semi-major axis of 1.41 AU). I ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1981 Midas
1981 Midas, provisional designation , is a vestoid asteroid, classified as a near-Earth object and potentially hazardous asteroid, approximately 2 kilometers in diameter. It was discovered on 6 March 1973 by American astronomer Charles Kowal at Palomar Observatory in San Diego County, California. It was named after King Midas from Greek mythology. Classification and orbit The moderately bright V-type asteroid is also an Apollo asteroid, as well as a Venus and Mars-crosser. The asteroid orbits the Sun at a distance of 0.6–2.9 AU once every 2 years and 4 months (864 days). Its orbit has an eccentricity of 0.65 and an inclination of 40 ° with respect to the ecliptic. ''Midas'' has a low minimum orbit intersection distance with Earth of , which corresponds to 1.5 lunar distance (Earth–Moon distance). However, it does not pose an impact risk for the foreseeable future. On 19 March 1947 it passed from Earth. The last notable close approach was on 21 March 2018 passing f ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1866 Sisyphus
1866 Sisyphus 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 given the provisional designation . It was named after Sisyphus from Greek mythology. Orbit and classification 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. The Apollo asteroid has an ''Earth minimum orbit intersection distance'' of , which corresponds to 40.4 lunar distances. It will pass from Earth on 24 November 2071, and will peak at roughly apparent magnitude 9.3 on 26 November 2071. When it was discovered it peaked at magnitude 9.0 on 25 November 1972. It is one of the brightest near-Earth a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1865 Cerberus
1865 Cerberus is a stony asteroid and near-Earth object of the Apollo group, approximately 1.6 kilometers in diameter. It was discovered on 26 October 1971, by Czech astronomer Luboš Kohoutek at the Hamburger Bergedorf Observatory, Germany, and given the provisional designation . It was named for Cerberus from Greek mythology. Orbit and classification ''Cerberus'' orbits the Sun at a distance of 0.6–1.6 AU once every 1 years and 1 month (410 days). Its orbit has an eccentricity of 0.47 and an inclination of 16 ° with respect to the ecliptic. The Apollo asteroid has an ''Earth minimum orbital intersection distance'' of , which corresponds to 61 lunar distances. It passes within 30 gigametres ( Gm) of the Earth 7 times from the year 1900 to the year 2100, each time at a distance of 24.4 Gm to 25.7 Gm. It also makes close approaches to Mars and Venus. Physical characteristics In the Tholen and SMASS taxonomy, ''Cerberus'' is a common stony S-type asteroid, compos ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1864 Daedalus
1864 Daedalus, provisional designation , is a stony asteroid and near-Earth object of the Apollo group, approximately 3 kilometers in diameter. It was discovered on 24 March 1971, by Dutch–American astronomer Tom Gehrels at Palomar Observatory, California, and named after Daedalus from Greek mythology. Orbit and classification ''Daedalus'' is a member of the Apollo asteroids, a group of near-Earth object with an Earth-crossing orbit. It orbits the Sun in the inner main-belt at a distance of 0.6–2.4 AU once every 1 years and 9 months (645 days). Its orbit has an eccentricity of 0.61 and an inclination of 22 ° with respect to the ecliptic. It has an Earth ''Minimum orbit intersection distance'' (MOID) of 0.2693 AU. Physical characteristics ''Daedalus'' is a stony asteroid, characterized as an SQ and Sr spectral type in the Tholen and SMASS taxonomy. Diameter and albedo According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1863 Antinous
1863 Antinous , provisional designation , is a stony asteroid and near-Earth object, approximately 2–3 kilometers in diameter. It was discovered on 7 March 1948 by American astronomer Carl Wirtanen at Lick Observatory on the summit of Mount Hamilton, California. It was named after Antinous from Greek mythology. Orbit and classification ''Antinous'' is also classified as a Mars-crosser and Apollo asteroid. The SU/Sq-type asteroid orbits the Sun in the inner main-belt at a distance of 0.9–3.6 AU once every 3 years and 5 months (1,240 days). Its orbit has an eccentricity of 0.61 and an inclination of 18 ° with respect to the ecliptic. It has an Earth ''Minimum orbit intersection distance'' (MOID) of 0.1836 AU. In the 20th century ''Antinous'' passed within 30 Gm of the Earth five times; it will do so only once in the 21st. The nearest distance increases each time, from 26 to 29 Gm. Physical characteristics In the Tholen and SMASS taxonomic scheme, ' ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1862 Apollo
1862 Apollo is a stony asteroid, approximately 1.5 kilometers in diameter, classified as a near-Earth object (NEO). It was discovered by German astronomer Karl Reinmuth at Heidelberg Observatory on 24 April 1932, but lost and not recovered until 1973. It is the namesake and the first recognized member of the Apollo asteroids, a subgroup of NEOs which are Earth-crossers, that is, they cross the orbit of the Earth when viewed perpendicularly to the ecliptic plane (crossing an orbit is a more general term than actually intersecting it). In addition, since Apollo's orbit is highly eccentric, it crosses the orbits of Venus and Mars and is therefore called a Venus-crosser and Mars-crosser as well. Although Apollo was the first Apollo asteroid to be discovered, its official IAU-number (1862) is higher than that of some other Apollo asteroids such as 1566 Icarus, due to the fact that it was a lost asteroid for more than 40 years and other bodies were numbered in the meantime. The anal ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1685 Toro
1685 Toro ( ''prov. designation'': ) is an asteroid and near-Earth object of the Apollo group on an eccentric orbit. It was discovered on 17 July 1948, by American astronomer Carl Wirtanen at Lick Observatory on Mount Hamilton, California. The stony S-type asteroid has a rotation period of 10.2 hours and measures approximately in diameter. It is named for Betulia Toro Herrick, wife of astronomer Samuel Herrick. Classification and orbit Toro is an Apollo asteroid, a subgroup of near-Earth asteroids that cross the orbit of Earth. It orbits the Sun at a distance of 0.8–2.0 AU once every 584 days. Its orbit has an eccentricity of 0.44 and an inclination of 9 ° with respect to the ecliptic. This asteroid's orbit also shows a 5:8 resonance with Earth and in a near 5:13 resonance with Venus. This near resonance results from Earth and Venus being in a near 8:13 resonance with each other. It was the third Apollo asteroid to be discovered. The current resonance with Earth ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |