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Airy-0
Airy-0 is a crater inside the larger Airy Crater on Mars, whose location defined the position of the prime meridian of that planet. It is about 0.5 km (0.3 mile) across and lies within the dark region Sinus Meridiani, one of the early albedo features to be identified on Mars. The IAU Working Group on Cartographic Coordinates and Rotational Elements has now recommended setting the longitude of the Viking 1 lander (47.95137° west) as the standard. This definition maintains the position of the center of Airy-0 at 0° longitude, within the tolerance of current cartographic uncertainties. Merton Davies tied this crater into an extensive geodetic control network of the planet Mars based on Mariner 9 and earlier photographs. The Mariner 9 Geodesy/Cartography Group proposed that the prime meridian of Mars be defined by the center of Airy-0, which was selected by Harold Masursky, Gerard de Vaucouleurs, and Merton Davies at a Group meeting on 14 August 1972. It was named i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airy (Martian Crater)
Airy may refer to: * Sir George Biddell Airy (1801–1892), British Astronomer Royal from 1835 to 1881, for whom the following features, phenomena, and theories are named: ** Airy (lunar crater) ** Airy (Martian crater) ** Airy-0, a smaller crater within the previous one on Mars, and which defines the prime meridian of the planet ** Airy wave theory, a linear theory describing the propagation of "gravity waves" on the surface of a fluid ** Airy disk, a diffraction pattern in optics ** Airy beam, a non-spreading, transversely accelerating optical wavepacket ** Airy function, a mathematical function ** Airy points, support points chosen to minimize the distortion of the length of a physical standard (such as the International Prototype Meter) * Anna Airy (1882–1964), British artist * Airy (software), a video-downloading utility * Airy, a character in the video game ''Bravely Default'' See also * Airey (other) * Mount Airy (other) * Aerie (other) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terrestrial planet with a thin atmosphere (less than 1% that of Earth's), and has a crust primarily composed of elements similar to Earth's crust, as well as a core made of iron and nickel. Mars has surface features such as impact craters, valleys, dunes and polar ice caps. It has two small and irregularly shaped moons, Phobos (moon), Phobos and Deimos (moon), Deimos. Some of the most notable surface features on Mars include Olympus Mons, the largest volcano and List of tallest mountains in the Solar System, highest known mountain in the Solar System and Valles Marineris, one of the largest canyons in the Solar System. The North Polar Basin (Mars), Borealis basin in the Northern Hemisphere covers approximately 40% of the planet and may be a la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Biddell Airy
Sir George Biddell Airy (; 27 July 18012 January 1892) was an English mathematician and astronomer, and the seventh Astronomer Royal from 1835 to 1881. His many achievements include work on planetary orbits, measuring the mean density of the Earth, a method of solution of two-dimensional problems in solid mechanics and, in his role as Astronomer Royal, establishing Greenwich as the location of the prime meridian. Biography Airy was born at Alnwick, one of a long line of Airys who traced their descent back to a family of the same name residing at Kentmere, in Westmorland, in the 14th century. The branch to which he belonged, having suffered in the English Civil War, moved to Lincolnshire and became farmers. Airy was educated first at elementary schools in Hereford, and afterwards at Colchester Royal Grammar School. An introverted child, Airy gained popularity with his schoolmates through his great skill in the construction of peashooters. From the age of 13, Airy stayed frequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prime Meridian
A prime meridian is an arbitrary meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°. Together, a prime meridian and its anti-meridian (the 180th meridian in a 360°-system) form a great circle. This great circle divides a spheroid, like the Earth, into two hemispheres: the Eastern Hemisphere and the Western Hemisphere (for an east-west notational system). For Earth's prime meridian, various conventions have been used or advocated in different regions throughout history. The Earth's current international standard prime meridian is the IERS Reference Meridian. It is derived, but differs slightly, from the Greenwich Meridian, the previous standard. A prime meridian for a planetary body not tidally locked (or at least not in synchronous rotation) is entirely arbitrary, unlike an equator, which is determined by the axis of rotation. However, for celestial objects that are tidally locked (more specifically, synchronous), th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Reconnaissance Orbiter
''Mars Reconnaissance Orbiter'' (MRO) is a spacecraft designed to study the geology and climate of Mars, provide reconnaissance of future landing sites, and relay data from surface missions back to Earth. It was launched on August 12, 2005, and reached Mars on March 10, 2006. In November 2006, after five months of aerobraking, it entered its final science orbit and began its primary science phase. The cost to develop and operate MRO through the end of its prime mission in 2010 was . The spacecraft continues to operate at Mars, far beyond its intended design life. Due to its critical role as a high-speed data-relay for ground missions, NASA intends to continue the mission as long as possible, at least through the late 2020s. Pre-launch After the twin failures of the ''Mars Climate Orbiter'' and the Mars Polar Lander missions in 1999, NASA reorganized and replanned its Mars Exploration Program. In October 2000, NASA announced its reformulated Mars plans, which reduced the numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerard De Vaucouleurs
Gerard is a masculine forename of Proto-Germanic origin, variations of which exist in many Germanic and Romance languages. Like many other early Germanic names, it is dithematic, consisting of two meaningful constituents put together. In this case, those constituents are ''gari'' > ''ger-'' (meaning 'spear') and -''hard'' (meaning 'hard/strong/brave'). Common forms of the name are Gerard (English, Scottish, Irish, Dutch, Polish and Catalan); Gerrard (English, Scottish, Irish); Gerardo (Italian, and Spanish); Geraldo (Portuguese); Gherardo (Italian); Gherardi (Northern Italian, now only a surname); Gérard (variant forms ''Girard'' and ''Guérard'', now only surnames, French); Gearóid (Irish); Gerhardt and Gerhart/Gerhard/Gerhardus (German, Dutch, and Afrikaans); Gellért ( Hungarian); Gerardas ( Lithuanian) and Gerards/Ģirts ( Latvian); Γεράρδης (Greece). A few abbreviated forms are Gerry and Jerry (English); Gerd (German) and Gert (Afrikaans and Dutch); Gerrit (A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Margaritifer Sinus Quadrangle
The Margaritifer Sinus quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Margaritifer Sinus quadrangle is also referred to as MC-19 (Mars Chart-19). The Margaritifer Sinus quadrangle covers the area from 0° to 45° west longitude and 0° to 30° south latitude on Mars. Margaritifer Sinus quadrangle contains Margaritifer Terra and parts of Xanthe Terra, Noachis Terra, Arabia Terra, and Meridiani Planum. The name of this quadrangle means "pearl bay" after the pearl coast at Cape Comorin in South India. This quadrangle shows many signs of past water with evidence of lakes, deltas, ancient rivers, inverted channels, and chaos regions that released water. Margaritifer Sinus contains some of the longest lake-chain systems on Mars, perhaps because of a wetter climate, more groundwater, or some of each factor. The Samara/Himera lake-chain system is about 1800 km long; the Parar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters On Mars
__NOTOC__ This is a list of craters on Mars. Impact craters on Mars larger than exist by the hundreds of thousands, but only about one thousand of them have names. Names are assigned by the International Astronomical Union after petitioning by relevant scientists, and in general, only craters that have a significant research interest are given names. Martian craters are named after famous scientists and science fiction authors, or if less than in diameter, after towns on Earth. Craters cannot be named for living people, and names for small craters are rarely intended to commemorate a specific town. Latitude and longitude are given as planetographic coordinates with west longitude. Catalog of named craters The catalog is divided into three partial lists: * List of craters on Mars: A–G * List of craters on Mars: H–N * List of craters on Mars: O–Z Names are grouped into tables for each letter of the alphabet, containing the crater's name (linked if article exists), coord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Observatory, Greenwich
The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, temporarily moved south from Greenwich to Herstmonceux) is an observatory situated on a hill in Greenwich Park in south east London, overlooking the River Thames to the north. It played a major role in the history of astronomy and navigation, and because the Prime Meridian passes through it, it gave its name to Greenwich Mean Time, the precursor to today's Coordinated Universal Time (UTC). The ROG has the IAU observatory code of 000, the first in the list. ROG, the National Maritime Museum, the Queen's House and the clipper ship ''Cutty Sark'' are collectively designated Royal Museums Greenwich. The observatory was commissioned in 1675 by King Charles II, with the foundation stone being laid on 10 August. The old hilltop site of Greenwich Castle was chosen by Sir Christopher Wren, a former Savilian Professor of Astronomy; as Greenw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transit Circle
The meridian circle is an instrument for timing of the passage of stars across the local meridian, an event known as a culmination, while at the same time measuring their angular distance from the nadir. These are special purpose telescopes mounted so as to allow pointing only in the meridian, the great circle through the north point of the horizon, the north celestial pole, the zenith, the south point of the horizon, the south celestial pole, and the nadir. Meridian telescopes rely on the rotation of the sky to bring objects into their field of view and are mounted on a fixed, horizontal, east–west axis. The similar transit instrument, transit circle, or transit telescope is likewise mounted on a horizontal axis, but the axis need not be fixed in the east–west direction. For instance, a surveyor's theodolite can function as a transit instrument if its telescope is capable of a full revolution about the horizontal axis. Meridian circles are often called by these names, althou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomer Royal
Astronomer Royal is a senior post in the Royal Households of the United Kingdom. There are two officers, the senior being the Astronomer Royal dating from 22 June 1675; the junior is the Astronomer Royal for Scotland dating from 1834. The post was created by King Charles II in 1675, at the same time as he founded the Royal Observatory Greenwich. He appointed John Flamsteed, instructing him "." The Astronomer Royal was director of the Royal Observatory Greenwich from the establishment of the post in 1675 until 1972. The Astronomer Royal became an honorary title in 1972 without executive responsibilities and a separate post of Director of the Royal Greenwich Observatory was created to manage the institution. The Astronomer Royal today receives a stipend of 100 GBP per year and is a member of the Royal Household, under the general authority of the Lord Chamberlain. After the separation of the two offices, the position of Astronomer Royal has been largely honorary, though the ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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