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Yardangs On Mars
Yardangs are common in some regions on Mars, especially in the Medusae Fossae Formation. This formation is found in the Amazonis quadrangle and near the equator. They are formed by the action of wind on sand sized particles; hence they often point in the prevailing direction that the winds were blowing when they were formed. Because they exhibit very few impact craters they are believed to be relatively young. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash. Yardangs are parts of rock that have been sand blasted into long, skinny ridges by bouncing sand particles blowing in the wind.Yardangs in Arsinoes Chaos University of Arizona HiRISE Operations, 04 January 2015 Layers are seen i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zooming On The Yardangs Of Mount Sharp With Remote Micro Imager - Sol 1994
Zoom may refer to: Technology Computing * Zoom (software), videoconferencing application * Page zooming, the ability to magnify or shrink a portion of a page on a computer display * Zooming user interface, a graphical interface allowing for image scaling * Digital zoom, an electronic emulation of a zoom lens Optics * Zoom ratio, the maximum relative to the minimum magnification factor of an optical system * Zoom lens, a lens system with a variable focal length, and hence variable magnification and angle of view * Zooming (filmmaking), a cinematographic effect Companies * Zoomcar, a carsharing company in India * Zoom (video game company), a Japanese video-game company * Zoom Airlines Inc., a former Canadian airline ** Zoom Airlines Limited, its former British sister company * Zoom Corporation, a Japanese audio company * ZOOM Erlebniswelt Gelsenkirchen, a zoological park in Gelsenkirchen, Germany * ZoomInfo (formerly Zoom Information), an American software company * Zoom Systems, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medusae Fossae Formation
The Medusae Fossae Formation is a large geological formation of probable volcanic origin on the planet Mars. It is named for the Medusa of Greek mythology. "Fossae" is Latin for "trenches". The formation is a collection of soft, easily eroded deposits that extends discontinuously for more than 5,000 km along the equator of Mars. Its roughly-shaped regions extend from just south of Olympus Mons to Apollinaris Patera, with a smaller additional region closer to Gale Crater. The total area of the formation is equal to 20% the size of the continental United States. It is divided into three subunits (members) that are all considered to be of Amazonian age, the youngest era in martian geological history. The formation straddles the highland - lowland boundary near the Tharsis and Elysium volcanic areas, and extends across five quadrangles: Amazonis, Tharsis, Memnonia, Elysium, and Aeolis. Origin and age The origin of the formation is unknown, but many theories have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazonis Quadrangle
The Amazonis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Amazonis quadrangle is also referred to as MC-8 (Mars Chart-8). The quadrangle covers the area from 135° to 180° west longitude and 0° to 30° north latitude on Mars. The Amazonis quadrangle contains the region called Amazonis Planitia. This area is thought to be among the youngest parts of Mars because it has a very low density of craters. The Amazonian Epoch is named after this area. This quadrangle contains special, unusual features called the Medusae Fossae Formation and Sulci. Medusae Fossae Formation The Amazonis quadrangle is of great interest to scientists because it contains a big part of a formation, called the Medusae Fossae Formation. It is a soft, easily eroded deposit that extends for nearly 1,000 km along the equator of Mars. The surface of the formation has been eroded by the wind into a series ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Express
''Mars Express'' is a space exploration mission being conducted by the European Space Agency (ESA). The ''Mars Express'' mission is exploring the planet Mars, and is the first planetary mission attempted by the agency. "Express" originally referred to the speed and efficiency with which the spacecraft was designed and built. However, "Express" also describes the spacecraft's relatively short interplanetary voyage, a result of being launched when the orbits of Earth and Mars brought them closer than they had been in about 60,000 years. ''Mars Express'' consists of two parts, the ''Mars Express Orbiter'' and ''Beagle 2'', a lander designed to perform exobiology and geochemistry research. Although the lander failed to fully deploy after it landed on the Martian surface, the orbiter has been successfully performing scientific measurements since early 2004, namely, high-resolution imaging and mineralogical mapping of the surface, radar sounding of the subsurface structure down to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer to all explosive eruption products (correctly referred to as ''tephra''), including particles larger than 2 mm. Volcanic ash is formed during explosive volcanic eruptions when dissolved gases in magma expand and escape violently into the atmosphere. The force of the gases shatters the magma and propels it into the atmosphere where it solidifies into fragments of volcanic rock and glass. Ash is also produced when magma comes into contact with water during phreatomagmatic eruptions, causing the water to explosively flash to steam leading to shattering of magma. Once in the air, ash is transported by wind up to thousands of kilometres away. Due to its wide dispersal, ash can have a number of impacts on society, including animal a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yardang
A yardang is a streamlined protuberance carved from bedrock or any consolidated or semiconsolidated material by the dual action of wind abrasion by dust and sand and deflation (the removal of loose material by wind turbulence.) Yardangs become elongated features typically three or more times longer than wide, and when viewed from above, resemble the hull of a boat. Facing the wind is a steep, blunt face that gradually gets lower and narrower toward the lee end. Yardangs are formed by wind erosion, typically of an originally flat surface formed from areas of harder and softer material. The soft material is eroded and removed by the wind, and the harder material remains. The resulting pattern of yardangs is therefore a combination of the original rock distribution, and the fluid mechanics of the air flow and resulting pattern of erosion. Names The word itself is of Turkic origin, meaning ‘steep bank’, as this type of spectacular landscapes rising are best developed in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Global Surveyor
''Mars Global Surveyor'' (MGS) was an American robotic space probe developed by NASA's Jet Propulsion Laboratory and launched November 1996. MGS was a global mapping mission that examined the entire planet, from the ionosphere down through the atmosphere to the surface. As part of the larger Mars Exploration Program, Mars Global Surveyor performed atmospheric monitoring for sister orbiters during aerobraking, and helped Mars rovers and lander missions by identifying potential landing sites and relaying surface telemetry. It completed its primary mission in January 2001 and was in its third extended mission phase when, on 2 November 2006, the spacecraft failed to respond to messages and commands. A faint signal was detected three days later which indicated that it had gone into safe mode. Attempts to recontact the spacecraft and resolve the problem failed, and NASA officially ended the mission in January 2007. MGS remains in a stable near-polar circular orbit at about 450 km ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HiRISE
High Resolution Imaging Science Experiment is a camera on board the ''Mars Reconnaissance Orbiter'' which has been orbiting and studying Mars since 2006. The 65 kg (143 lb), US$40 million instrument was built under the direction of the University of Arizona's Lunar and Planetary Laboratory by Ball Aerospace & Technologies Corp. It consists of a 0.5m (19.7 in) aperture reflecting telescope, the largest so far of any deep space mission, which allows it to take pictures of Mars with resolutions of 0.3m/pixel (1ft/pixel), resolving objects below a meter across. HiRISE has imaged Mars exploration rovers on the surface, including the ''Opportunity'' rover and the ongoing ''Curiosity'' mission. History In the late 1980s, of Ball Aerospace & Technologies began planning the kind of high-resolution imaging needed to support sample return and surface exploration of Mars. In early 2001 he teamed up with Alfred McEwen of the University of Arizona to propose such a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cementation (geology)
Cementation involves ions carried in groundwater chemically precipitating to form new crystalline material between sedimentary grains. The new pore-filling minerals forms "bridges" between original sediment grains, thereby binding them together. In this way, ''sand'' becomes sandstone, and ''gravel'' becomes conglomerate or breccia. Cementation occurs as part of the diagenesis or lithification of sediments. Cementation occurs primarily below the water table regardless of sedimentary grain sizes present. Large volumes of pore water must pass through sediment pores for new mineral cements to crystallize and so millions of years are generally required to complete the cementation process. Common mineral cements include calcite, quartz, and silica phases like cristobalite, iron oxides, and clay minerals; other mineral cements also occur. Cementation is continuous in the groundwater zone, so much so that the term "zone of cementation" is sometimes used interchangeably. Cementati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
THEMIS
In Greek mythology and Ancient Greek religion, religion, Themis (; grc, Θέμις, Themis, justice, law, custom) is one of the twelve Titans, Titan children of Gaia and Uranus (mythology), Uranus, and the second wife of Zeus. She is the goddess and personification of justice, divine order, fairness, law, and custom, and her symbols include the Scales of Justice (symbol), Scales of Justice. She is also associated with oracles and prophecies, including the Pythia, Oracle of Delphi. Name ''Themis'' means "divine law" rather than human ordinance, literally "that which is put in place", from the Greek verb ''títhēmi'' (wikt:τίθημι, τίθημι), meaning "to put." To the ancient Greeks she was originally the organizer of the "communal affairs of humans, particularly assemblies." Moses Finley remarked of ''themis'', as the word was used by Homer in the 8th century BCE, to evoke the social order of the 10th- and 9th-century Greek Dark Ages: Finley adds, "There was ''them ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transverse Aeolian Ridges
Transverse aeolian ridges (TARs) are visually bright features commonly found in topographic depressions on Mars. These small-scale and relict bedforms were first seen in narrow-angle images from the Mars Orbiter Camera (MOC) and were called “ridges” to preserve both dunes and ripples as formative mechanisms. While TARs are widespread on Mars, their formation, age, composition, and role in past Martian sediment cycles remain poorly constrained. Aeolian bedforms Aeolian bedforms are typically classified into either ripples or dunes based on their morphologies and formative mechanisms. Dunes are larger (>0.5 m or taller on Earth), typically asymmetrical in cross-profile, and are the product of hydrodynamic instability related to sand flux, the local topography, shear stress exerted by the wind on sand grains, and flow-form interactions induced by the topography of the dune itself. Wind ripples by comparison are small (amplitudes of 0.6 - 15 mm), are more symmetrical in profile, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeolis Quadrangle
The Aeolis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Aeolis quadrangle is also referred to as MC-23 (Mars Chart-23). The Aeolis quadrangle covers 180° to 225° W and 0° to 30° south on Mars, and contains parts of the regions Elysium Planitia and Terra Cimmeria. A small part of the Medusae Fossae Formation lies in this quadrangle. The name refers to the name of a floating western island of Aeolos, the ruler of the winds. In Homer's account, Odysseus received the west wind Zephyr here and kept it in bags, but the wind got out. It is famous as the site of two spacecraft landings: the ''Spirit'' rover landing site () in Gusev crater (January 4, 2004), and the ''Curiosity'' rover in Gale Crater () (August 6, 2012). A large, ancient river valley, called Ma'adim Vallis, enters at the south rim of Gusev Crater, so Gusev Crater was believed to be an ancient lake bed. However, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
