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4055 Magellan
4055 Magellan, provisional designation , is a bright and eccentric asteroid and near-Earth object of the Amor group, approximately 2.5 kilometers in diameter. It was discovered on 24 February 1985, by American astronomer Eleanor Helin at Palomar Observatory in California, United States. It was later named for Portuguese explorer Ferdinand Magellan. Orbit and classification ''Magellan'' orbits the Sun in the inner main-belt at a distance of 1.2–2.4 AU once every 2 years and 6 months (897 days). Its orbit has an eccentricity of 0.33 and an inclination of 23 ° with respect to the ecliptic. The first observation was made at the Australian Siding Spring Observatory, extending the asteroid's observation arc by just one month prior to its official discovery observation at Palomar. It has a minimum orbital intersection distance with Earth of , which corresponds to 93.4 lunar distances. Physical characteristics Being a V-type asteroid in the Tholen and SMASS taxonomy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eleanor F
Eleanor () is a feminine given name, originally from an Old French adaptation of the Old Provençal name ''Aliénor''. It is the name of a number of women of royalty and nobility in western Europe during the High Middle Ages. The name was introduced to England by Eleanor of Aquitaine, who came to marry King Henry II. It was also borne by Eleanor of Provence, who became Queen consort of England as the wife of King Henry III, and Eleanor of Castile, wife of Edward I. The name was popular in the United States in the 1910s and 1920s, peaking at rank 25 in 1920. It declined below 600 by the 1970s, again rose to rank 32 in the 2010s. Eleanor Roosevelt, the longest-serving first lady of the US was probably the most famous bearer of the name in contemporary history. Common hypocorisms include Elle, Ella, Ellie, Elly, Leonor, Leonora, Leonore, Nella, Nellie, Nelly, and Nora. Origin The name derives from the Provençal name Aliénor, which became Eléonore in ''Langue d'oïl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eleanor 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 several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keck Observatory
The W. M. Keck Observatory is an astronomical observatory with two telescopes at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii. Both telescopes have aperture primary mirrors, and when completed in 1993 (Keck 1) and 1996 (Keck 2) were the largest astronomical telescopes in the world. They are currently the 3rd and 4th largest. Overview With a concept first proposed in 1977, telescope designers at the University of California, Berkeley (Terry Mast) and Lawrence Berkeley Laboratory (Jerry Nelson) had been developing the technology necessary to build a large, ground-based telescope. With a design in hand, a search for the funding began. In 1985, Howard B. Keck of the W. M. Keck Foundation gave $70 million to fund the construction of the Keck I telescope, which began in September 1985, with first light occurring on 24 November 1990 using nine of the eventual 36 segments. With construction of the first telescope well ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1 Ceres
Ceres (; minor-planet designation: 1 Ceres) is a dwarf planet in the asteroid belt between the orbits of Mars and Jupiter. It was the first asteroid discovered, on 1 January 1801, by Giuseppe Piazzi at Palermo Astronomical Observatory in Sicily and announced as a new planet. Ceres was later classified as an asteroid and then a dwarf planetthe only one always inside Neptune's orbit. Ceres's small size means that even at its brightest, it is too dim to be seen by the naked eye, except under extremely dark skies. Its apparent magnitude ranges from 6.7 to 9.3, peaking at opposition (when it is closest to Earth) once every 15- to 16-month synodic period. As a result, its surface features are barely visible even with the most powerful telescopes, and little was known about it until the robotic NASA spacecraft ''Dawn'' approached Ceres for its orbital mission in 2015. ''Dawn'' found Ceres's surface to be a mixture of water ice, and hydrated minerals such as carbonates and clay. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4 Vesta
Vesta (minor-planet designation: 4 Vesta) is one of the largest objects in the asteroid belt, with a mean diameter of . It was discovered by the German astronomer Heinrich Wilhelm Matthias Olbers on 29 March 1807 and is named after Vesta, the virgin goddess of home and hearth from Roman mythology. Vesta is thought to be the second-largest asteroid, both by mass and by volume, after the dwarf planet Ceres, though in volume it overlaps with the uncertainty in the measurements of 2 Pallas.Marsset, M., Brož, M., Vernazza, P. et al. The violent collisional history of aqueously evolved (2) Pallas. Nat Astron 4, 569–576 (2020). https://doi.org/10.1038/s41550-019-1007-5 Measurements give it a nominal volume only slightly larger than that of Pallas (about 5% greater, which is the magnitude of the uncertainties in measurement), but it is 25% to 30% more massive. It constitutes an estimated 9% of the mass of the asteroid belt. Vesta is the only known remaining rocky protoplanet (with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Lunar impact craters range from microscopic craters on lunar rocks returned by the Apollo Program and small, simple, bowl-shaped depressions in the lunar regolith to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth. Impact craters are the dominant geographic features on many solid Solar System objects including the Moon, Mercury, Callisto, Ganymede and most small moons and asteroids. On other planets and moons that experience more active surface geological processes, such as Earth, Venus, Europa, Io and Titan, visible impact craters are less common because they become eroded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheasilvia
Rheasilvia is the most prominent surface feature on the asteroid Vesta and is thought to be an impact crater. It is in diameter, which is 90% the diameter of Vesta itself, and is 95% the mean diameter of Vesta, . However, the mean is affected by the crater itself. It is 89% the mean equatorial diameter of , making it one of the largest craters in the Solar System, and at 75°S latitude, covers most of the southern hemisphere. The peak in the center of the crater is in diameter, and rises from its base, making it one of the tallest mountains known in the Solar System. Discovery Rheasilvia was discovered in Hubble Space Telescope images in 1997, but was not named until the arrival of the ''Dawn'' spacecraft in 2011. It is named after Rhea Silvia, a mythological vestal virgin and mother of the founders of Rome, Romulus and Remus.(NASA coordinates) Characteristics The crater partially obscures an earlier crater, named Veneneia, that at is almost as large. Rheasilvia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum Orbital Intersection Distance
Minimum orbit intersection distance (MOID) is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. It is defined as the distance between the closest points of the osculating orbits of two bodies. Of greatest interest is the risk of a collision with Earth. Earth MOID is often listed on comet and asteroid databases such as the JPL Small-Body Database. MOID values are also defined with respect to other bodies as well: Jupiter MOID, Venus MOID and so on. An object is classified as a potentially hazardous object (PHO) – that is, posing a possible risk to Earth – if, among other conditions, its Earth MOID is less than 0.05 AU. For more massive bodies than Earth, there is a potentially notable close approach with a larger MOID; for instance, Jupiter MOIDs less than 1 AU are considered noteworthy since Jupiter is the most massive planet.Bruce Koehn,Minimum Orbital Intersection Distance, Lowell Observatory, retrieved o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observation Arc
In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly used in the discovery and tracking of asteroids and comets. Arc length has the greatest influence on the accuracy of an orbit. The number and spacing of intermediate observations has a lesser effect. Short arcs A very short arc leaves a high uncertainty parameter. The object might be in one of many different orbits, at many distances from Earth. In some cases, the initial arc was too short to determine if the object was in orbit around the Earth, or orbiting out in the asteroid belt. With a 1-day observation arc, was thought to be a trans-Neptunian dwarf planet, but is now known to be a 1 km main-belt asteroid. With an observation arc of 3 days, was thought to be a Mars-crossing asteroid that could be a threat to Earth, but was later ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siding Spring Observatory
Siding Spring Observatory near Coonabarabran, New South Wales, Australia, part of the Research School of Astronomy & Astrophysics (RSAA) at the Australian National University (ANU), incorporates the Anglo-Australian Telescope along with a collection of other telescopes owned by the Australian National University, the University of New South Wales, and other institutions. The observatory is situated above sea level in the Warrumbungle National Park on Mount Woorat, also known as Siding Spring Mountain. Siding Spring Observatory is owned by the Australian National University (ANU) and is part of the Mount Stromlo and Siding Spring Observatories research school. More than 100 million worth of research equipment is located at the observatory. There are over 60 telescopes on site, though not all are operational. History The original Mount Stromlo Observatory was set up by the Commonwealth Government in 1924. After duty supplying optical components to the military in World W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecliptic
The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the background of stars. The ecliptic is an important reference plane and is the basis of the ecliptic coordinate system. Sun's apparent motion The ecliptic is the apparent path of the Sun throughout the course of a year. Because Earth takes one year to orbit the Sun, the apparent position of the Sun takes one year to make a complete circuit of the ecliptic. With slightly more than 365 days in one year, the Sun moves a little less than 1° eastward every day. This small difference in the Sun's position against the stars causes any particular spot on Earth's surface to catch up with (and stand directly north or south of) the Sun about four minutes later each day than it would if Earth did not orbit; a day on Earth is therefore 24 hours ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or 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 degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planet's equator. For pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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