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South Pole Of The Moon
The lunar south pole is the southernmost point on the Moon. It is of interest to scientists because of the occurrence of water ice in permanently shadowed areas around it. The lunar south pole region features craters that are unique in that the near-constant sunlight does not reach their interior. Such craters are cold traps that contain fossil records of hydrogen, water ice, and other volatiles dating from the early Solar System. In contrast, the lunar north pole region exhibits a much lower quantity of similarly sheltered craters. Geography The lunar south pole is located on the center of the polar Antarctic Circle (80°S to 90°S).Lunar South Pole. NASA. 2017. Accessed on 16 July 2019. (The axis spin is 88.5 degrees from the plane of the ecliptic.) The lunar south pole has shifte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shackleton Crater
Shackleton is an impact crater that lies at the lunar south pole. The peaks along the crater's rim are exposed to almost continual sunlight, while the interior is permanently shadowed crater, perpetually in shadow. The low-temperature interior of this crater functions as a cold trap that may capture and freeze Volatile (astrogeology), volatiles shed during comet impacts on the Moon. Measurements by the ''Lunar Prospector'' spacecraft showed higher than normal amounts of hydrogen within the crater, which may indicate the presence of water ice. The crater is named after Antarctic explorer Ernest Shackleton. Description The rotational axis of the Moon passes through Shackleton, near the rim. The crater is in diameter and deep. From the Earth, it is viewed edge-on in a region of rough, cratered terrain. It is located within the South Pole–Aitken basin on a massif. The rim is slightly raised about the surrounding surface and it has an outer rampart that has been only lightly imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sverdrup (crater)
Sverdrup is a lunar impact crater that is located about one crater diameter from the southern pole of the Moon. It lies on the far side of the Moon with respect to the Earth, in an area of the surface that is only illuminated by very oblique light from the Sun. The interior part of the crater is cloaked in perpetual darkness, and thus has not been mapped using photography. Portions of the rim are illuminated, however, and give the appearance of a worn formation that has been intruded upon by adjacent formations. The nearest craters of note to Sverdrup are de Gerlache to the east, and Shackleton at the south pole. References * * * * * * * * * * * * External links * {{cite news , title = Diviner lunar south pole image , publisher = UCLA The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California, United States. Its academic roots were established in 1881 as a normal school then kno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups. Both the negatively charged anion , called hydroxide, and the neutral radical , known as the hydroxyl radical, consist of an unbonded hydroxy group. According to IUPAC definitions, the term ''hydroxyl'' refers to the hydroxyl radical () only, while the functional group is called a ''hydroxy group''. Properties Water, alcohols, carboxylic acids, and many other hydroxy-containing compounds can be readily deprotonated due to a large difference between the electronegativity of oxygen (3.5) and that of hydrogen (2.1). Hydroxy-containing compounds engage in intermolecular hydrogen bonding increasing the electrostatic attraction between molecules and thus to higher boiling and melting points than found for compounds that lack thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteorite
A meteorite is a rock (geology), rock that originated in outer space and has fallen to the surface of a planet or Natural satellite, moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a Meteoroid#Fireball, fireball, also known as a shooting star; astronomers call the brightest examples "Bolide#Astronomy, bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater. Meteorites that are recovered after being observed as they transit the atmosphere and impact event, impact Earth are called meteorite falls. All others are known as meteorite finds. Meteorites have traditionally been divided into three broad categories: stony meteorites that are rocks, mainly composed of sil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet
A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding the nucleus, and sometimes a Comet tail, tail of gas and dust gas blown out from the coma. These phenomena are due to the effects of solar radiation and the outstreaming solar wind plasma acting upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times Earth's diameter, while the tail may stretch beyond one astronomical unit. If sufficiently close and bright, a comet may be seen from Earth without the aid of a telescope and can Subtended angle, subtend an arc of up to 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures and religion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Trap (astronomy)
A cold trap is a concept in planetary sciences that describes an area cold enough to freeze (trap) volatiles. Cold-traps can exist on the surfaces of airless bodies or in the upper layers of an adiabatic atmosphere. On airless bodies, the ices trapped inside cold-traps can potentially remain there for geologic time periods, allowing us a glimpse into the primordial solar system. In adiabatic atmospheres, cold-traps prevent volatiles (such as water) from escaping the atmosphere into space. Cold-traps on airless planetary bodies The obliquity (axial tilt) of some airless planetary bodies in the Solar System such as Mercury, the Moon and Ceres is very close to zero. Harold Urey first noted that depressions or craters located near the poles of these bodies will cast persistent shadows that can survive for geologic time periods (millions–billions of years). The absence of an atmosphere prevents mixing by convection, rendering these shadows extremely cold. If molecules of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma (physics)
Plasma () is a state of matter characterized by the presence of a significant portion of charged particles in any combination of ions or electrons. It is the most abundant form of ordinary matter in the universe, mostly in stars (including the Sun), but also dominating the rarefied intracluster medium and Outer space#Intergalactic space, intergalactic medium. Plasma can be artificially generated, for example, by heating a neutral gas or subjecting it to a strong electromagnetic field. The presence of charged particles makes plasma electrically conductive, with the dynamics of individual particles and macroscopic plasma motion governed by collective electromagnetic fields and very sensitive to externally applied fields. The response of plasma to electromagnetic fields is used in many modern devices and technologies, such as plasma display, plasma televisions or plasma etching. Depending on temperature and density, a certain number of neutral particles may also be present, in wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backscatter
In physics, backscatter (or backscattering) is the reflection of waves, particles, or signals back to the direction from which they came. It is usually a diffuse reflection due to scattering, as opposed to specular reflection as from a mirror, although specular backscattering can occur at normal incidence with a surface. Backscattering has important applications in astronomy, photography, and medical ultrasonography. The opposite effect is forward scatter, e.g. when a translucent material like a cloud diffuses sunlight, giving soft light. Backscatter of waves in physical space Backscattering can occur in quite different physical situations, where the incoming waves or particles are deflected from their original direction by different mechanisms: *Diffuse reflection from large particles and Mie scattering, causing alpenglow and gegenschein, and showing up in weather radar; *Inelastic collisions between electromagnetic waves and the transmitting medium ( Brillouin scattering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Wind
The solar wind is a stream of charged particles released from the Sun's outermost atmospheric layer, the Stellar corona, corona. This Plasma (physics), plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the solar wind plasma also includes a mixture of particle species found in the solar plasma: trace amounts of heavy ions and atomic nuclei of Chemical element, elements such as carbon, nitrogen, oxygen, neon, magnesium, silicon, sulfur, and iron. There are also rarer traces of some other nuclei and isotopes such as phosphorus, titanium, chromium, and nickel's isotopes 58Ni, 60Ni, and 62Ni. Superimposed with the solar-wind plasma is the interplanetary magnetic field. The solar wind varies in density, temperature and speed over time and over Solar coordinate systems#Heliographic, solar latitude and longitude. Its particles can escape the Sun's gravity because of their high energy resulting from the high temperature of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Reconnaissance Orbiter
The Lunar Reconnaissance Orbiter (LRO) is a NASA robotic spacecraft currently orbiting the Moon in an eccentric Polar orbit, polar mapping orbit. Data collected by LRO have been described as essential for planning NASA's future human and robotic missions to the Moon. Its detailed mapping program is identifying safe landing sites, locating potential resources on the Moon, characterizing the radiation environment, and demonstrating new technologies. Launched on June 18, 2009, in conjunction with the LCROSS, Lunar Crater Observation and Sensing Satellite (LCROSS), as the vanguard of NASA's Lunar Precursor Robotic Program, LRO was the first United States mission to the Moon in over ten years. LRO and LCROSS were launched as part of the United States's Vision for Space Exploration program. The probe has made a 3-D map of the Moon's surface at 100-meter resolution and 98.2% coverage (excluding polar areas in deep shadow), including 0.5-meter resolution images of Apollo landing sites. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cabeus (crater)
Cabeus is a lunar impact crater that is located about from the south pole of the Moon. At this location the crater is seen obliquely from Earth, and it is almost perpetually in deep shadow due to lack of sunlight. Hence, not much detail can be seen of this crater, even from orbit. Through a telescope, this crater appears near the southern limb of the Moon, to the west of the crater Malapert and to the south-southwest of Newton. Description The crater name ''Cabeus'' first appeared in the 1651 work ''Almagestum Novum'' by Giovanni Riccioli, who named it after Niccolò Cabeo. However, the position of the Cabeus crater was in the location later assigned to Newton crater.Whitaker (1999:61, 211) The official name and location for this crater was adopted by the IAU Commission 17, as established in the 1935 work ''Named Lunar Formations'' by Mary A. Blagg and Karl Müller. This crater is a worn formation that has been eroded by subsequent impacts. The rim is eroded and une ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nobile (crater)
Nobile is a lunar impact crater that is located near the southern pole of the Moon. It was named after the Italian aviator and explorer Umberto Nobile by the International Astronomical Union (IAU) in 1994. It lies to the south of the crater Scott, along the western rim of Amundsen. Between Nobile and the southern pole lie the smaller craters Shoemaker and Faustini. This is an eroded crater formation that is almost constantly cloaked in deep shadows. When sunlight does enter the interior of this crater, it does so at a very oblique angle. The crater rim is overlaid by several lesser craters, the most notable being a formation about half the diameter of Nobile along the western rim. There are also small craters along the southwest and northern parts of the rim. The outer rampart of Amundsen overlies the eastern rim and inner wall. The interior floor of this crater is somewhat irregular, and there are a few small craterlets across the surface. Nobile was previously designated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
