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Mars Geyser Hopper
The Mars Geyser Hopper (MGH) is a NASA design reference mission for a Discovery-class spacecraft concept that would investigate the springtime carbon dioxide Martian geysers found in regions around the south pole of Mars. The power technology that MGH proposed to use was the Advanced Stirling radioisotope generator ( ASRG). NASA finished the ASRG design and made one test unit of the device but the program was concluded by the mid-2010s. Neither InSight nor any of the next Discovery's semi-finalists use the ASRG or an RTG due to high demand and limited supply of the type of plutonium it relies on. Background The Discovery program was started in the 1990s following discussions at NASA for a new program, and has achieved such missions as ''Genesis'', ''Deep Impact'' and ''Kepler'' among others; this is the program this mission was designed for selection in, at least initially. One of the first unmanned robotic spacecraft to do a hop was Surveyor 6 lunar lander, which successfu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Landing
A Mars landing is a landing of a spacecraft on the surface of Mars. Of multiple attempted Mars landings by robotic, uncrewed spacecraft, ten have had successful soft landings. There have also been studies for a possible human mission to Mars, including a landing, but none have been attempted. Soviet Union’s Mars 3, which landed in 1971, was the first successful Mars landing. As of May 2021, the Soviet Union, United States, and China have conducted Mars landings successfully. Methods of descent and landing As of 2021, all methods of landing on Mars have used an aeroshell and parachute sequence for Mars atmospheric entry and descent, but after the parachute is detached, there are three options. A stationary lander can drop from the parachute back shell and ride retrorockets all the way down, but a rover cannot be burdened with rockets that serve no purpose after touchdown. One method for lighter rovers is to enclose the rover in a tetrahedral structure which in turn is encl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LIDAR
Lidar (, also LIDAR, or LiDAR; sometimes LADAR) is a method for determining ranges (variable distance) by targeting an object or a surface with a laser and measuring the time for the reflected light to return to the receiver. It can also be used to make digital 3-D representations of areas on the Earth's surface and ocean bottom of the intertidal and near coastal zone by varying the wavelength of light. It has terrestrial, airborne, and mobile applications. ''Lidar'' is an acronym of "light detection and ranging" or "laser imaging, detection, and ranging". It is sometimes called 3-D laser scanning, a special combination of 3-D scanning and laser scanning. Lidar is commonly used to make high-resolution maps, with applications in surveying, geodesy, geomatics, archaeology, geography, geology, geomorphology, seismology, forestry, atmospheric physics, laser guidance, airborne laser swath mapping (ALSM), and laser altimetry. It is also used in control and navigation for som ... [...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 directly observed in detail from the Earth with help from a telescope. Although Mars is smaller than the Earth, 11% of Earth's mass, and 50% farther from the Sun than the 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' climate has similarities to Earth's, including periodic ice ages, there are also important differences, such as much lower thermal inertia. Mars' 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. The climate briefly received more interest in the news due to NASA measurements indicating increased sublima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rille
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 one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Geophysical Research
The ''Journal of Geophysical Research'' is a peer-reviewed scientific journal. It is the flagship journal of the American Geophysical Union. It contains original research on the physical, chemical, and biological processes that contribute to the understanding of the Earth, Sun, and Solar System. It has seven sections: A (Space Physics), B (Solid Earth), C (Oceans), D (Atmospheres), E (Planets), F (Earth Surface), and G (Biogeosciences). All current and back issues are available online for subscribers. History The journal was originally founded under the name ''Terrestrial Magnetism'' by the American Geophysical Union's president Louis Agricola Bauer in 1896. It was renamed to ''Terrestrial Magnetism and Atmospheric Electricity'' in 1899 and in 1948 it acquired its current name. In 1980, three specialized sections were established: ''A: Space Physics'', ''B: Solid Earth'', and ''C: Oceans''. Subsequently, further sections have been added: ''D: Atmospheres'' in 1984, ''E: Planets'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geyser
A geyser (, ) is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in a few places on Earth. Generally all geyser field sites are located near active volcanic areas, and the geyser effect is due to the proximity of magma. Generally, surface water works its way down to an average depth of around where it contacts hot rocks. The resultant boiling of the pressurized water results in the geyser effect of hot water and steam spraying out of the geyser's surface vent (a hydrothermal explosion). A geyser's eruptive activity may change or cease due to ongoing mineral deposition within the geyser plumbing, exchange of functions with nearby hot springs, earthquake influences, and human intervention. Like many other natural phenomena, geysers are not unique to Earth. Jet-like eruptions, often referred to as cryoge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geysers On Mars
Martian geysers (or jets) are putative sites of small gas and dust eruptions that occur in the south polar region of Mars during the spring thaw. "Dark dune spots" and "spiders" – or araneiforms – are the two most visible types of features ascribed to these eruptions. Martian geysers are distinct from geysers on Earth, which are typically associated with hydrothermal activity. These are unlike any terrestrial geological phenomenon. The reflectance (albedo), shapes and unusual spider appearance of these features have stimulated a variety of hypotheses about their origin, ranging from differences in frosting reflectance, to explanations involving biological processes. However, all current geophysical models assume some sort of jet or geyser-like activity on Mars. Their characteristics, and the process of their formation, are still a matter of debate. These features are unique to the south polar region of Mars in an area informally called the 'cryptic region', at latitudes 6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martian CO2 Gas Venting
Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. It became the most popular celestial object in fiction in the late 1800s as the Moon was evidently lifeless. At the time, the predominant genre depicting Mars was utopian fiction. Contemporaneously, the mistaken belief that there are canals on Mars emerged and made its way into fiction. ''The War of the Worlds'', H. G. Wells' story of an alien invasion of Earth by sinister Martians, was published in 1897 and went on to have a large influence on the science fiction genre. Life on Mars appeared frequently in fiction throughout the first half of the 1900s. Apart from enlightened as in the utopian works from the turn of the century, or evil as in the works inspired by Wells, intelligent and human-like Martians also began to be depicted as decadent, a portrayal that was popularized by Edgar Rice Burroughs in the ''Barsoom'' series and adopted by Leigh Brackett among other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
