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Airy-0
Airy-0 is a crater inside the larger Airy Crater on Mars, whose location historically defined the Martian prime meridian. 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. In 2018, the IAU Working Group on Cartographic Coordinates and Rotational Elements recommended setting the longitude of the Viking 1 lander (47.95137° west) as the reference line. 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 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 * Christopher Airy (1934–2025), British Army officer * Airy, a character in the video game ''Bravely Default'' * Airy (musician), South Korean indie pop musician See also * Airey (other) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Mars
Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmospheric pressure is a few thousandths of Earth's, atmospheric temperature ranges from and cosmic radiation is high. Mars retains some water, in the ground as well as thinly in the atmosphere, forming cirrus clouds, frost, larger polar regions of permafrost and ice caps (with seasonal snow), but no liquid surface water. Its surface gravity is roughly a third of Earth's or double that of the Moon. It is half as wide as Earth or twice the Moon, with a diameter of , and has a surface area the size of all the dry land of Earth. Fine dust is prevalent across the surface and the atmosphere, being picked up and spread at the low Martian gravity even by the weak wind of the tenuous atmosphere. The terrain of Mars roughly follows a north-south ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
George Biddell Airy
Sir George Biddell Airy (; 27 July 18012 January 1892) was an English mathematician and astronomer, as well as the Lucasian Professor of Mathematics from 1826 to 1828 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 in Northumberland, 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 grea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Prime Meridian
A prime meridian is an arbitrarily chosen meridian (geography), meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°. On a spheroid, a prime meridian and its anti-meridian (the 180th meridian in a degree (angle), 360°-system) form a great ellipse. This divides the body (e.g. Earth) into hemispheres of Earth, 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. Earth's current international standard prime meridian is the IERS Reference Meridian. It is derived, but differs slightly, from the Prime meridian (Greenwich), Greenwich Meridian, the previous standard. Longitudes for the Earth and Moon are measured from their prime meridian (at 0°) to 180° east and west. For all other Solar System bodies, longitude is measured from 0° (their prime meridian) to 360� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Mars Reconnaissance Orbiter
The ''Mars Reconnaissance Orbiter'' (''MRO'') is a spacecraft designed to search for the existence of water on Mars and provide support for missions to Mars, as part of NASA's Mars Exploration Program. It was launched from Cape Canaveral on August 12, 2005, at 11:43 UTC and reached Mars on March 10, 2006, at 21:24 UTC. In November 2006, after six months of aerobraking, it entered its final science orbit and began its primary science phase. Mission objectives include observing the climate of Mars, investigating geologic forces, providing reconnaissance of future landing sites, and relaying data from surface missions back to Earth. To support these objectives, the ''MRO'' carries different scientific instruments, including three cameras, two spectrometers and a subsurface radar. As of July 29, 2023, the ''MRO'' has returned over 450 terabits of data, helped choose safe landing sites for NASA's Mars landers, discovered pure water ice in new craters and further evidence that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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); (Italian, and Spanish); ( Portuguese); (Italian); (Northern Italian, now only a surname); (variant forms and , now only surnames, French); ( Irish); Gerhardt and Gerhart/Gerhard/Gerhardus (German, Dutch, and Afrikaans); ( Hungarian); ( Lithuanian) and / ( Latvian); (Greece). A few abbreviated forms are Gerry and Jerry (English); (German) and (Afrikaans and Dutch); (Afrikaans and Dutch); (Afrikaans); (Dutch) and ( Bulgarian). The introduction of the name 'Gerard' into the English languag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Margaritifer Sinus Quadrangle
The Margaritifer Sinus quadrangle is one of a series of list of quadrangles on Mars, 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 (geography), 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 Pearl Fishery Coast, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 Martian craters are listed alphabetically on the following 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 e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 (Greenwich), Prime Meridian passed 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 Charles II of England, 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 for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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, alth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 Astronomer Royal works to make observations to improve navigation, cartography, instrument design, and applications of geomagnetism. The position was created with the overall goal of discovering a way to determine longitude at sea when out of sight of land. History The post was created by Charles II in 1675, at the same time as he founded the Royal Observatory, Greenwich. He appointed John Flamsteed, instructing him "." The first six Astronomer Royals dedicated themselves primarily to this task and focused on astronomical observations that would benefit navigation. 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 197 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
