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Sinuous Rilles
Rille (German for 'groove') is typically used to describe any of the long, narrow depressions in the surface of the Moon that resemble channels. The Latin term is ''rima'', plural ''rimae''. Typically, a rille can be several kilometers wide and hundreds of kilometers in length. However, the term has also been used loosely to describe similar structures on a number of planets in the Solar System, including Mars, Venus, and on a number of moons. All bear a structural resemblance to each other. Structures Three types of rille are found on the lunar surface: * Sinuous rilles meander in a curved path like a mature river, and are commonly thought to be the remains of collapsed lava tubes or extinct lava flows. They usually begin at an extinct volcano, then meander and sometimes split as they are followed across the surface. , 195 sinuous rilles have been identified on the Moon. Vallis Schröteri in Oceanus Procellarum is the largest sinuous rille, and Rima Hadley is the only o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanus Procellarum
Oceanus Procellarum ( ; from ) is a vast lunar mare on the western edge of the near side of the Moon. It is the only one of the lunar maria to be called an "Oceanus" (ocean), due to its size: Oceanus Procellarum is the largest of the maria ("seas"), stretching more than across its north–south axis and covering roughly , accounting for 10.5% of the total lunar surface area. Characteristics Like all lunar maria, Oceanus Procellarum was formed by ancient volcanic eruptions resulting in basaltic floods that covered the region in a thick, nearly flat layer of solidified magma. Basalts in Oceanus Procellarum have been estimated to be as young as one billion years old. Unlike the other lunar maria, however, Oceanus Procellarum may or may not be contained within a single, well-defined impact basin. Around its edges lie many minor bays and seas, including Sinus Roris to the north, and Mare Nubium, Mare Humorum and to the south. To the northeast, Oceanus Procellarum is separated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rima Ariadaeus
Rima Ariadaeus is a linear rille on the lunar surface, situated at coordinates . Measuring approximately 5 km (3.1 mi) in width and spanning a length of 300 km (186.4 mi), it stretches between Mare Tranquillitatis and Mare Vaporum. Formation Some scientists think that the linear rilles might have formed after large impact events, while others believe that the rilles were formed as a surface manifestation of deep-seated dike systems when the Moon was still volcanically active. Rima Ariadaeus is thought to have been formed when a section of the Moon's crust sank down between two parallel fault lines (making it a graben or fault trough). Rima Ariadaeus shows no trace of associated volcanism and is thus considered to be an end member of the sequence where only pure faulting is involved i.e. a linear rille. Age The ridges crossing the rille trough of Rima Ariadaeus and the surrounding plains units have been offset by the trough, proving that the ridges are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vallis Alpes
Vallis Alpes (Latin for "Alpine Valley") is a lunar valley feature that bisects the Montes Alpes range. It extends 166 km from the Mare Imbrium basin, trending east-northeast to the edge of the Mare Frigoris. The valley is narrow at both ends and widens to a maximum width of about 10 km along the middle stretch. The selenographic coordinates of the center of this feature are . The valley floor is a flat, lava-flooded surface that is bisected by a slender, broken, cleft-like rille. The center rille is a challenging target for telescope observation from the Earth and described as, "notoriously hard to spot." The rille itself is longer than the valley proper, at 196.65 km ± 10.98 km, and has a width of 0.58 km ± 0.09 km and depth of 77.69 m ± 28.07 m. The sides of the valley rise from the floor to the surrounding highland terrain, a blocky, irregular surface. The southern face of the valley is straighter than the northern side, which is slightly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Crater
An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, 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. Impact craters are typically circular, though they can be elliptical in shape or even irregular due to events such as landslides. Impact craters range in size from microscopic craters seen on lunar rocks returned by the Apollo Program to simple bowl-shaped depressions and vast, 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 (planet), Mercury, Callisto (moon), Callisto, Ganymede (moon), Ganymede, and most small moons and asteroids. On other planet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the plane that represents the fracture surface of a fault. A '' fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geological maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graben
In geology, a graben () is a depression (geology), depressed block of the Crust (geology), crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German language, German, meaning 'ditch' or 'trench'. The first known usage of the word in the geologic context was by Eduard Suess in 1883. The plural form is either ''graben'' or ''grabens''. Formation A graben is a valley with a distinct escarpment on each side caused by the displacement of a block of land downward. Graben often occur side by side with Horst (geology), horsts. Horst and graben structures indicate tensional forces and crustal stretching. Graben are produced by sets of normal faults that have parallel fault traces, where the displacement of the hanging wall is downward, while that of the footwall is upward. The faults typically dip toward the center of the graben from both sides. Horsts are parallel blocks that remain between graben; the bounding faults of a horst t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mare Serenitatis
Mare Serenitatis (Latin ''serēnitātis'', the "Sea of Serenity") is a lunar mare located to the east of Mare Imbrium on the Moon. Its diameter is . Geology Mare Serenitatis is located within the Serenitatis basin, which is of the Nectarian epoch. The material surrounding the mare is of the Lower Imbrian epoch, while the mare material is of the Upper Imbrian epoch. The mare basalt covers a majority of the basin and overflows into Lacus Somniorum to the northeast. The most noticeable feature is the crater Posidonius on the northeast rim of the mare. The ring feature to the west of the mare is indistinct, except for Montes Haemus. Mare Serenitatis connects with Mare Tranquillitatis to the southeast and borders Mare Vaporum to the southwest. Mare Serenitatis is an example of a mascon, an anomalous gravitational region on the Moon. A mass concentration (mascon), or gravitational high, was identified in the center of Mare Serenitatis from Doppler tracking of the five L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulpicius Gallus (crater)
Sulpicius Gallus is a small, bowl-shaped Lunar craters, lunar impact crater that lies near the southwestern edge of the Mare Serenitatis. The crater is named after the 2nd century BC Roman astronomer Gaius Sulpicius Gallus. About 10 kilometers to the south and east is the Montes Haemus range that forms the edge of the Serenitatis basin. This crater has a relatively high albedo, with a sharp-edged rim that displays little appearance of wear. There is a small rise at the midpoint. Recent deposits of highland material have been observed within the crater interior. This material was observed to be orange by Apollo 17 astronauts during their LMP ascent. To the northwest is a rille system designated the Rimae Sulpicius Gallus. These extend to the northwest for a distance of about 90 kilometers, curving and branching out to follow the edge of the mare. Satellite craters By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mare Humorum
Mare Humorum (Latin ''hūmōrum'', the "Sea of Moisture" or "Sea of Humors") is a lunar mare. The impact basin it is located in is across. Geology It was not sampled by the Apollo program, so a precise age has not been determined. However, geological mapping indicates that it is intermediate in age between the Imbrium and Nectaris Basins, suggesting an age of about 3.9 billion years. The Humorum basin is filled with a thick layer of mare basalt, believed to exceed 3 kilometers in thickness at the center of the basin. A mass concentration (mascon), or gravitational high, was identified in the center of Mare Humorum from Doppler tracking of the five Lunar Orbiter spacecraft in 1968. The mascon was confirmed and mapped at higher resolution with later orbiters such as Lunar Prospector and GRAIL. On the north edge of Mare Humorum is the large crater Gassendi, which was considered as a possible landing site for Apollo 17. To the south are the floor-fractured Vitello c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mare Tranquillitatis
Mare Tranquillitatis (Latin for Sea of Tranquillity or Sea of Tranquility) is a lunar mare that sits within the Tranquillitatis basin on the Moon. It contains Tranquility Base, the first location on another celestial body to be visited by humans. The mare material within the basin consists of basalt formed in the intermediate to young age group of the Upper Imbrian epoch. The surrounding mountains are thought to be of the Lower Imbrian epoch, but the actual basin is probably Pre-Nectarian. The basin has irregular margins and lacks a defined multiple-ringed structure. The irregular topography in and near this basin results from the intersection of the Tranquillitatis, Mare Nectaris, Nectaris, Mare Crisium, Crisium, Mare Fecunditatis, Fecunditatis, and Mare Serenitatis, Serenitatis basins with two throughgoing rings of the Oceanus Procellarum, Procellarum basin. Palus Somni, on the northeastern rim of the mare, is filled with the basalt that spilled over from Tranquillitatis. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Mare
The lunar maria ( ; mare ) are large, dark, basaltic plains on Earth's Moon, formed by lava flowing into ancient impact basins. They are less reflective than the "highlands" as a result of their iron-rich composition, and hence appear dark to the naked eye. The maria cover about 16% of the lunar surface, mostly on the side visible from Earth. The few maria on the far side are much smaller, residing mostly in very large craters. The traditional nomenclature for the Moon also includes one (ocean), as well as features with the names ('lake'), ('marsh'), and ('bay'). The last three are smaller than maria, but have the same nature and characteristics. The names of maria refer to sea features ( Mare Humorum, Mare Imbrium, Mare Insularum, Mare Nubium, Mare Spumans, Mare Undarum, Mare Vaporum, Oceanus Procellarum, Mare Frigoris), sea attributes ( Mare Australe, Mare Orientale, Mare Cognitum, Mare Marginis), or states of mind ( Mare Crisium, Mare Ingenii, Mare Serenita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
