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Polygonal Patterned Ground
Polygonal, patterned ground is quite common in some regions of Mars. It is commonly believed to be caused by the sublimation of ice from the ground. Sublimation is the direct change of solid ice to a gas. This is similar to what happens to dry ice on the Earth. Places on Mars that display polygonal ground may indicate where future colonists can find water ice. Low center polygons have been proposed as a marker for ground ice. Polygonal terrain is also found on earth's permafrost. Patterned ground forms in a mantle layer, called latitude dependent mantle, that fell from the sky when the climate was different. On Mars, researches have found patterned ground that formed from fractures and patterned ground formed by the arrangement of boulders. It is not yet clear what caused boulders to form patterns, but it does not seem that fractures caused the boulders to move around. Esp 037167 1445mantle.jpg, Surface showing appearance with and without mantle covering, as seen by HiRIS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sublimation (phase Transition)
Sublimation is the Phase transition, transition of a substance directly from the solid to the gas state, without passing through the liquid state. The verb form of sublimation is ''sublime'', or less preferably, ''sublimate''. ''Sublimate'' also refers to the product obtained by sublimation. The point at which sublimation occurs rapidly (for further details, see #False correspondence with vaporization, below) is called critical sublimation point, or simply sublimation point. Notable examples include sublimation of dry ice at room temperature and atmospheric pressure, and that of solid iodine with heating. The reverse process of sublimation is deposition (phase transition), ''deposition'' (also called ''desublimation''), in which a substance passes directly from a gas to a solid phase, without passing through the liquid state. Technically, all solids may sublime, though most sublime at extremely low rates that are hardly detectable under usual conditions. At standard condi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deuteronilus Mensae
Deuteronilus Mensae is a region on Mars 937 km across and centered at . It covers 344°–325° West and 40°–48° North. Deuteronilus region lies just to the north of Arabia Terra and is included in the Ismenius Lacus quadrangle. It is along the dichotomy boundary, that is between the old, heavily cratered southern highlands and the low plains of the northern hemisphere. The region contains flat-topped knobby terrain that may have been formed by glaciers at some time in the past. Deuteronilus Mensae is to the immediate west of Protonilus Mensae and Ismeniae Fossae. Glaciers persist in the region in modern times, with at least one glacier estimated to have formed as recently as 100,000 to 10,000 years ago. Recent evidence from the radar on the Mars Reconnaissance Orbiter has shown that parts of Deuteronilus Mensae do indeed contain ice. Source of ice It is now widely believed that ice accumulated in many areas of Mars, including Deuteronilus Mensae, when the planet's o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latitude Dependent Mantle
Much of the Martian surface is covered with a thick ice-rich, mantle layer that has fallen from the sky a number of times in the past. In some places a number of layers are visible in the mantle. Image:Layered mantle in Icaria Planum.JPG, Layers in mantle deposit, as seen by HiRISE, under the HiWish program. Mantle was probably formed from snow and dust falling during a different climate. Location is Thaumasia quadrangle ESP 039721 1400mantlelayers.jpg, HiRISE image showing smooth mantle covering parts of a crater in the Phaethontis quadrangle. Along the outer rim of the crater, the mantle is displayed as layers. This suggests that the mantle was deposited multiple times in the past. Picture was taken with HiRISE under HiWish program. The layers are enlarged in the next image. ESP 039721 1400mantlelayersclose.jpg, Enlargement of previous image of mantle layers. Four to five layers are visible. Location is the Phaethontis quadrangle. Esp 037167 1445mantle.jpg, Surface sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Of Mars
The climate of Mars has been a topic of scientific curiosity for centuries, in part because it is the only terrestrial planet whose surface can be easily directly observed in detail from Earth with help from a telescope. Although Mars is smaller than Earth with only one tenth of Earth's mass, and 50% farther from the Sun than Earth, its climate has important similarities, such as the presence of polar ice caps, seasonal changes and observable weather patterns. It has attracted sustained study from planetologists and climatologists. While Mars's climate has similarities to Earth's, including periodic ice ages, there are also important differences, such as much lower thermal inertia. Mars's atmosphere has a scale height of approximately , 60% greater than that on Earth. The climate is of considerable relevance to the question of whether life is or ever has been present on the planet. Mars has been studied by Earth-based instruments since the 17th century, but it is only since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patterned Ground
Patterned ground is the distinct and often symmetrical natural pattern of geometric shapes formed by the deformation of ground material in periglacial regions. It is typically found in remote regions of the Arctic, Antarctica, and the Outback in Australia, but is also found anywhere that freezing and thawing of soil alternate; patterned ground has also been observed in the hyper-arid Atacama Desert and on Mars. The geometric shapes and patterns associated with patterned ground are often mistaken as artistic human creations. The mechanism of the formation of patterned ground had long puzzled scientists but the introduction of computer-generated geological models in the past 20 years has allowed scientists to relate it to frost heaving, the expansion that occurs when wet, fine-grained, and porous soils freeze. Types Patterned ground can be found in a variety of forms. Typically, the type of patterned ground in a given area is related to the prevalence of larger stones in l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arkhangelsky Crater
Arkhangelsky (masculine), Arkhangelskaya (feminine), or Arkhangelskoye (neuter) may refer to: People * Arkhangelsky (surname) Places * Arkhangelsky District, a district in the Republic of Bashkortostan, Russia * Arkhangelsky (rural locality) (''Arkhangelskaya'', ''Arkhangelskoye''), name of several rural localities in Russia *Arkhangelsk Oblast (''Arkhangelskaya oblast''), a federal subject of Russia * Arkhanhelske, Donetsk Oblast, a village in Ukraine * Arkhanhelske, Kherson Oblast, a village in Ukraine Other uses *Arkhangelskoye Palace, a historical estate near Moscow, Russia * Arkhangelski, a Soviet military design bureau led by Alexander Arkhangelsky * Arkhangelsky Ar-2, a bomber designed by this design bureau * Arkhangelsky (crater), a crater on Mars named after him See also *Arkhangelsk Arkhangelsk (, ) is a types of inhabited localities in Russia, city and the administrative center of Arkhangelsk Oblast, Russia. It lies on both banks of the Northern Dvina near its mou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mare Acidalium Quadrangle
The Mare Acidalium 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 Quadrangle (geography), quadrangle is located in the northeastern portion of Mars' western hemisphere and covers 300° to 360° east longitude (0° to 60° west longitude) and 30° to 65° north latitude. The quadrangle uses a Lambert conformal conic projection at a nominal scale of 1:5,000,000 (1:5M). The Mare Acidalium quadrangle is also referred to as MC-4 (Mars Chart-4). The southern and northern borders of the quadrangle are approximately 3,065 km and 1,500 km wide, respectively. The north to south distance is about 2,050 km (slightly less than the length of Greenland). The quadrangle covers an approximate area of 4.9 million square km, or a little over 3% of Mars' surface area. Most of the region called Acidalia Planitia is found in Acidalium quadrangle. Parts of Te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phaethontis Quadrangle
The Phaethontis 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 Phaethontis quadrangle (geography), quadrangle is also referred to as MC-24 (Mars Chart-24). The name comes from Phaethon, the son of Helios. The Phaethontis quadrangle lies between 30° and 65° south latitude and 120° and 180° west longitude on Mars. This latitude range is where numerous gullies have been discovered. An old feature in this area, called Terra Sirenum lies in this quadrangle; Mars Reconnaissance Orbiter discovered iron/magnesium smectites there. Part of this quadrangle contains what is called the Electris deposits, a deposit that is thick. It is light-toned and appears to be weak because of few boulders. Among a group of large craters is Mariner Crater, first observed by the Mariner 4, Mariner 4 spacecraft in the summer of 1965. It was named after that spacecraft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lineated Valley Fill
Lineated valley fill (LVF), also called lineated floor deposit, is a feature of the floors of some channels on Mars, exhibiting ridges and grooves that seem to flow around obstacles. Shadow measurements show that at least some of the ridges are several metres high. LVF is believed to be ice-rich. Hundreds of metres of ice probably lie protected in LVF under a thin layer of debris. The debris consists of wind-borne dust, material from alcove walls, and lag material remaining after ice sublimated (changed from a solid directly to a gas) from a rock-ice mixture. Some glaciers on Earth show similar ridges. High-resolution pictures taken with HiRISE reveal that some of the surfaces of lineated valley fill are covered with strange patterns called closed-cell and open-cell brain terrain. The terrain resembles a human brain. It is believed to be caused by cracks in the surface accumulating dust and other debris, together with ice sublimating from some of the surfaces. The cracks are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain Terrain
Brain terrain, also called knobs-brain coral and brain coral terrain, is a feature of the Martian surface, consisting of complex ridges found on lobate debris aprons, lineated valley fill and concentric crater fill. It is so named because it suggests the ridges on the surface of the human brain. Wide ridges are called ''closed-cell'' brain terrain, and the less common narrow ridges are called ''open-cell'' brain terrain.Levy, J., J. Head, D. Marchant. 2009. Concentric crater fill in Utopia Planitia: History and interaction between glacial “brain terrain” and periglacial mantle processes. Icarus 202, 462–476. It is thought that the wide closed-cell terrain contains a core of ice, and when the ice disappears the center of the wide ridge collapses to produce the narrow ridges of the open-cell brain terrain. Shadow measurements from HiRISE indicate the ridges are 4-5 meters high. Brain terrain has been observed to form from what has been called an " Upper Plains Unit." The proce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argyre Quadrangle
The Argyre 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 Argyre quadrangle (geography), quadrangle is also referred to as MC-26 (Mars Chart-26). It contains Argyre Planitia and part of Noachis Terra. Name The word Argyre is named after a legendary silver at the mouth of the Ganges--[Arakan, Berma. The Argyre quadrangle covers the area from 0° to 60° west longitude and from 30° to 65° south latitude on Mars. It contains Galle (Martian crater), Galle crater, which resembles a smiley, smiley face and the Argyre Planitia, Argyre basin, a giant impact crater. Research published in the journal ''Icarus (journal), Icarus'' has found pits in Hale Crater that are caused by hot ejecta falling on ground containing ice. The pits are formed by heat forming steam that rushes out from groups of pits simultaneously, thereby blowing away from the pit ejecta. M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
