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E. F. Helin
Eleanor Francis "Glo" Helin (née Francis, 19 November 1932 – 25 January 2009) was an American astronomer. She was principal investigator of the Near-Earth Asteroid Tracking (NEAT) program of NASA's Jet Propulsion Laboratory. (Some sources give her name as Eleanor Kay Helin.) Helin was a prolific discoverer of minor planets ''(see list)'' and several comets, including periodic comets 111P/Helin–Roman–Crockett, 117P/Helin–Roman–Alu and 132P/Helin–Roman–Alu. She is credited as the discoverer of the object now known as both asteroid 4015 Wilson–Harrington and comet 107P/Wilson–Harrington. Although Wilson and Harrington preceded her by some decades, their observations did not establish an orbit for the object, while her rediscovery did. Helin discovered or co-discovered 903 asteroids and several comets. Biography Helin was born an only child to Fred and Kay Francis. At the age of five, she became ill with polio, which caused her to be bed-ridden for s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2100 Ra-Shalom
2100 Ra-Shalom ( ''prov. designation'': ) is an asteroid and near-Earth object of the Aten group on an eccentric orbit in the inner Solar System. It was discovered on 10 September 1978, by American astronomer Eleanor Helin at the Palomar Observatory, California, who named it in commemoration of the Camp David Peace Accords. The C-type asteroid (Xc, K) has a rotation period of 19.8 hours and measures approximately in diameter. Orbit and classification ''Ra-Shalom'' orbits the Sun at a distance of 0.5–1.2 AU once every 9 months (277 days). Its orbit has an eccentricity of 0.44 and an inclination of 16 ° with respect to the ecliptic. It was the second Aten asteroid to be discovered after 2062 Aten, the family's namesake, also discovered by Helin in 1976. The group of Aten asteroids feature a semi-major axis of less than 1 AU. Of this group, ''Ra-Shalom'' has one of the smallest semi-major axes, just 0.832 AU. The asteroid has an ''Earth minimum orb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert George Harrington
Robert George Harrington (December 3, 1904 – June 15, 1987) was an American astronomer who worked at Palomar Observatory. He should not be confused with Robert Sutton Harrington, who was also an astronomer, but was born later and worked at the US Naval Observatory. He discovered or co-discovered a number of comets, including periodic comets 43P/Wolf–Harrington, 51P/Harrington (discovered in 1953), 52P/Harrington–Abell (discovered jointly with George Ogden Abell in 1955) and the comet/asteroid 107P/Wilson–Harrington, which he and Albert George Wilson, Albert Wilson discovered in 1949 and which had become an asteroid by 1988. Google Books Harrington discovered the dwarf galaxy Leo II (dwarf galaxy), Leo II and co-discovered the globular cluster Palomar 12 with Fritz Zwicky. The asteroid 3216 Harrington was not named after Robert George Harrington, but rather after Robert Sutton Harrington. Harrington's name is, however, associated with the asteroid/comet 107P/Wilson†... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eccentricity (orbit)
In astrodynamics, the orbital eccentricity of an astronomical object is a dimensionless parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values between 0 and 1 form an elliptic orbit, 1 is a parabolic escape orbit (or capture orbit), and greater than 1 is a hyperbola. The term derives its name from the parameters of conic sections, as every Kepler orbit is a conic section. It is normally used for the isolated two-body problem, but extensions exist for objects following a rosette orbit through the Galaxy. Definition In a two-body problem with inverse-square-law force, every orbit is a Kepler orbit. The eccentricity of this Kepler orbit is a non-negative number that defines its shape. The eccentricity may take the following values: * circular orbit: ''e'' = 0 * elliptic orbit: 0 < ''e'' < 1 * [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1996 PW
is an exceptionally eccentric trans-Neptunian object and damocloid on an orbit typical of long-period comets but one that showed no sign of cometary activity around the time it was discovered. The Unusual minor planet, unusual object measures approximately in diameter and has a rotation period of 35.4 hours and likely an elongated shape. Description orbits the Sun at a distance of 2.5–504 Astronomical unit, AU once every 4,033 years (semi-major axis of 253 AU). Its orbit has an orbital eccentricity, eccentricity of 0.99 and an orbital inclination, inclination of 30Degree (angle), ° with respect to the ecliptic. Simulations indicate that it has most likely come from the Oort cloud, with a roughly equal probability of being an extinct comet and a rocky body that was originally scattered into the Oort cloud. The discovery of prompted theoretical research that suggests that roughly 1 to 2 percent of the Oort cloud objects are rocky. was first observed on 9 August ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near Earth Asteroid Tracking
Near-Earth Asteroid Tracking (NEAT) was a program run by NASA and the Jet Propulsion Laboratory, surveying the sky for near-Earth objects. NEAT was conducted from December 1995 until April 2007, at GEODSS on Hawaii (Haleakala-NEAT; 566), as well as at Palomar Observatory in California (Palomar-NEAT; 644). With the discovery of more than 40 thousand minor planets, NEAT has been one of the most successful programs in this field, comparable to the Catalina Sky Survey, LONEOS and Mount Lemmon Survey. NEAT was the successor to the Palomar Planet-Crossing Asteroid Survey (PCAS). History The original principal investigator was Eleanor F. Helin, with co-investigators Steven H. Pravdo and David L. Rabinowitz. NEAT has a cooperative agreement with the U.S. Air Force to use a GEODSS telescope located on Haleakala, Maui, Hawaii. GEODSS stands for Ground-based Electro-Optical Deep Space Surveillance and these wide field Air Force telescopes were designed to optically observe Earth or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Near-Earth Asteroid Survey
The International Near-Earth Asteroid Survey (INAS) was an astronomical survey, organized and co-ordinated by prolific American astronomer Eleanor Helin during the 1980s. It is considered to be the international extension of the Planet-Crossing Asteroid Survey (PCAS). While PCAS operated exclusively from the U.S. Palomar Observatory in California, INAS attempted to encourage and stimulate worldwide interest in asteroids, and to expand the sky coverage and the discovery and recovery of near-Earth objects around the world. The IAU's Minor Planet Center credits INAS with the discovery of 8 minor planets in 1986 (compared to 20 discoveries made by PCAS during 1993–1994). One of the discoveries was the 7-kilometer sized main-belt asteroid 4121 Carlin. See also *List of near-Earth object observation projects List of near-Earth object observation projects is a list of projects that observe Near-Earth objects. Most are astronomical surveys intended to find undiscovered asteroids. They ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near-Earth Asteroid
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). If a NEO's orbit crosses the Earth's orbit, and the object is larger than across, it is considered a potentially hazardous object (PHO). Most known PHOs and NEOs are asteroids, but a small fraction are comets. There are over 30,503 known near-Earth asteroids (NEAs) and over a hundred known short-period near-Earth comets (NECs). A number of solar-orbiting meteoroids were large enough to be tracked in space before striking the Earth. It is now widely accepted that collisions in the past have had a significant role in shaping the geological and biological history of the Earth. Asteroids as small as in diameter can cause significant damage to the local environment and human populations. Larger asteroids penetrate the atmosphere to the surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degree (angle), degrees. For a satellite orbiting a planet, the plane of reference is usually ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palomar Observatory
Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observatory is granted to Caltech and its research partners, which include the Jet Propulsion Laboratory (JPL), Yale University, and the National Optical Observatories of China. The observatory operates several telescopes, including the Hale Telescope, the Samuel Oschin Telescope (dedicated to the Zwicky Transient Facility, ZTF), the Palomar Telescope, and the Gattini-IR telescope. Decommissioned instruments include the Palomar Testbed Interferometer and the first telescopes at the observatory, an Schmidt camera from 1936. History Hale's vision for large telescopes and Palomar Observatory Astronomer George Ellery Hale, whose vision created the Palomar Observatory, built the world's largest telescope four times in succession. He publishe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palomar Planet-Crossing Asteroid Survey
The Palomar Planet-Crossing Asteroid Survey (PCAS) was an astronomical survey, initiated by American astronomers Eleanor Helin and Eugene Shoemaker at the U.S Palomar Observatory, California, in 1973. The program is responsible for the discovery of 95 near-Earth Objects including 17 comets, while the Minor Planet Center directly credits PCAS with the discovery of 20 numbered minor planets during 1993–1994. PCAS ran for nearly 25 years until June 1995. It had an international extension, INAS, and was the immediate predecessor of the outstandingly successful NEAT program. Notable discoveries The first NEO discovered by PACS was (5496) 1973 NA, an Apollo asteroid with an exceptional orbital inclination of 68 °, the most highly inclined minor planet known until 1999. In 1976, Eleanor Helin discovered 2062 Aten, the first of a new class of asteroids called the Aten asteroids with small orbits that are never far from Earth's orbit. As a result, these objects have a particularly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near Earth Objects
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). If a NEO's orbit crosses the Earth's orbit, and the object is larger than across, it is considered a potentially hazardous object (PHO). Most known PHOs and NEOs are asteroids, but a small fraction are comets. There are over 30,503 known near-Earth asteroids (NEAs) and over a hundred known short-period near-Earth comets (NECs). A number of solar-orbiting meteoroids were large enough to be tracked in space before striking the Earth. It is now widely accepted that collisions in the past have had a significant role in shaping the geological and biological history of the Earth. Asteroids as small as in diameter can cause significant damage to the local environment and human populations. Larger asteroids penetrate the atmosphere to the sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruce C
The English language name Bruce arrived in Scotland with the Normans, from the place name Brix, Manche in Normandy, France, meaning "the willowlands". Initially promulgated via the descendants of king Robert the Bruce (1274−1329), it has been a Scottish surname since medieval times; it is now a common given name. The variant ''Lebrix'' and ''Le Brix'' are French variations of the surname. Actors * Bruce Bennett (1906–2007), American actor and athlete * Bruce Boxleitner (born 1950), American actor * Bruce Campbell (born 1958), American actor, director, writer, producer and author * Bruce Davison (born 1946), American actor and director * Bruce Dern (born 1936), American actor * Bruce Gray (1936–2017), American-Canadian actor * Bruce Greenwood (born 1956), Canadian actor and musician * Bruce Herbelin-Earle (born 1998), English-French actor and model * Bruce Jones (born 1953), English actor * Bruce Kirby (1925–2021), American actor * Bruce Lee (1940–1973), martial ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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