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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] |
Thermal Emission Imaging System
The Thermal Emission Imaging System (THEMIS) is a camera on board the 2001 Mars Odyssey orbiter. It images Mars in the visible and infrared parts of the electromagnetic spectrum in order to determine the thermal properties of the surface and to refine the distribution of minerals on the surface of Mars as determined by the Thermal Emission Spectrometer (TES). Additionally, it helps scientists to understand how the mineralogy of Mars relates to its landforms, and it can be used to search for thermal hotspots in the Martian subsurface. THEMIS is managed from the Mars Space Flight Facility at Arizona State University and was built by the Santa Barbara Remote Sensing division of Raytheon Technologies Corporation, an American multinational conglomerate headquartered in Waltham, Massachusetts. The instrument is named after Themis, the goddess of justice in ancient Greek mythology. Infrared camera THEMIS detects thermal infrared energy emitted by the Martian surface at nine di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollinaris Mons
Apollinaris may refer to: Personal name * Apollinaris, a correspondent of Pliny the Younger (61–c. 112) * Apollinaris of Ravenna (flourished 1st or 2nd century), martyr and first bishop of Ravenna, the most prominent of several saints called Apollinaris * Apollinarius (astrologer), a first or second century AD astrologer * Apollinaris Claudius, Apollinaris of Hierapolis or Apollinaris the Apologist (flourished 2nd century), bishop of Hierapolis and saint * Apollinaris (the Elder) (flourished 4th century), Christian grammarian * Apollinaris of Laodicea or the Younger, also known as Apollinarius of Laodicea (died 390), bishop of Laodicea in Syria, author of the heresy of Apollinarism * Apollinaris Syncletica, also known as Dorotheus (5th century), female desert ascetic, Catholic and Eastern Orthodox saint * Apollinaris of Clermont (died 515), son of Sidonius Apollinaris * Apollinarius (governor), Byzantine governor of the Balearic Islands (flourished 530s) * Patriarch Apollina ... [...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] |
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] |
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] |
Prevailing Winds
In meteorology, prevailing wind in a region of the Earth's surface is a surface wind that blows predominantly from a particular direction. The dominant winds are the trends in direction of wind with the highest speed over a particular point on the Earth's surface at any given time. A region's prevailing and dominant winds are the result of global patterns of movement in the Earth's atmosphere. In general, winds are predominantly easterly at low latitudes globally. In the mid-latitudes, westerly winds are dominant, and their strength is largely determined by the polar cyclone. In areas where winds tend to be light, the sea breeze/land breeze cycle is the most important cause of the prevailing wind; in areas which have variable terrain, mountain and valley breezes dominate the wind pattern. Highly elevated surfaces can induce a thermal low, which then augments the environmental wind flow. Wind roses are tools used to display the direction of the prevailing wind. Knowledge of the ... [...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] |
Martian Soil
Martian soil is the fine regolith (a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock) found on the surface of Mars. Its properties can differ significantly from those of terrestrial soil, including its toxicity due to the presence of perchlorates. The term ''Martian soil'' typically refers to the finer fraction of regolith. So far, no samples have been returned to Earth, the goal of a Mars sample-return mission, but the soil has been studied remotely with the use of Mars rovers and Mars orbiters. On Earth, the term "soil" usually includes organic content. In contrast, planetary scientists adopt a functional definition of soil to distinguish it from rocks. Rocks generally refer to 10 cm scale and larger materials (e.g., fragments, breccia, and exposed outcrops) with high thermal inertia, with areal fractions consistent with the Viking Infrared Thermal Mapper (IRTM) data, and immobile under current aeolian (wind) conditions. Consequen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverted Relief
Inverted relief, inverted topography, or topographic inversion refers to landscape features that have reversed their elevation relative to other features. It most often occurs when low areas of a landscape become filled with lava or sediment that hardens into material that is more resistant to erosion than the material that surrounds it. ''Differential erosion'' then removes the less resistant surrounding material, leaving behind the younger resistant material, which may then appear as a ridge where previously there was a valley. Terms such as "inverted valley" or "inverted channel" are used to describe such features.Pain, C.F., and C.D. Ollier, 1995, ''Inversion of relief - a component of landscape evolution.'' Geomorphology. 12(2):151-165. Inverted relief has been observed on the surfaces of other planets as well as on Earth. For example, well-documented inverted topographies have been discovered on Mars.Pain, C.F., J.D.A. Clarke, and M. Thomas, 2007, ''Inversion of relief on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinuous Ridges In Medusae Formation
Sinuosity, sinuosity index, or sinuosity coefficient of a continuously differentiable curve having at least one inflection point is the ratio of the curvilinear length (along the curve) and the Euclidean distance (straight line) between the end points of the curve. This dimensionless quantity can also be rephrased as the "actual path length" divided by the "shortest path length" of a curve. The value ranges from 1 (case of straight line) to infinity (case of a closed loop, where the shortest path length is zero or for an infinitely-long actual path). Interpretation The curve must be continuous (no jump) between the two ends. The sinuosity value is really significant when the line is continuously differentiable (no angular point). The distance between both ends can also be evaluated by a plurality of segments according to a broken line passing through the successive inflection points (sinuosity of order 2). The calculation of the sinuosity is valid in a 3-dimensional space ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ignimbrite
Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surrounding atmosphere. New Zealand geologist Patrick Marshall (1869-1950) coined the term ''ignimbrite'' from the Latin ''igni-'' [fire] and ''imbri-'' [rain]. Ignimbrites are made of a very poorly sorted mixture of volcanic ash (or tuff when Lithification, lithified) and pumice lapilli, commonly with scattered lithic fragments. The ash is composed of glass shards and crystal fragments. Ignimbrites may be loose and unconsolidated, or lithified (solidified) rock called lapilli-tuff. Near the volcanic source, ignimbrites often contain thick accumulations of lithic blocks, and distally, many show meter-thick accumulations of rounded cobbles of pumice. Ignimbrites may be white, grey, pink, beige, brown, or black depending on their composition and d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Orbiter Laser Altimeter
260px, MOLA topographic images of the two hemispheres of Mars. This image appeared on the cover of ''Science'' magazine in May 1999. The Mars Orbiter Laser Altimeter (MOLA) was one of five instruments on the ''Mars Global Surveyor'' (MGS) spacecraft, which operated in Mars orbit from September 1997 to November 2006. However, the MOLA instrument transmitted altimetry data only until June 2001. The MOLA instrument transmitted infrared laser pulses towards Mars at a rate of 10 times per second, and measured the time of flight to determine the range (distance) of the MGS spacecraft to the Martian surface. The range measurements resulted in precise topographic maps of Mars. The precision maps are applicable to studies in geophysics, geology and atmospheric circulation. MOLA also functioned as a passive radiometer, and measured the radiance of the surface of Mars at 1064 nanometers. Planetary laser altimetry A laser altimeter is an instrument that measures the distance from an orbiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
