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Water On Mars
Although very small amounts of liquid water may occur transiently on the surface of Mars, limited to traces of dissolved moisture from the atmosphere and thin films, large quantities of ice are present on and under the surface. Small amounts of water vapor are present in the atmosphere, and liquid water may be present under the surface. In addition, a large quantity of liquid water was likely present on the surface in the distant past. Currently, ice is mostly present in polar permafrost. More than 5 million km3 of ice have been detected at or near the surface of Mars, enough to cover the planet to a depth of . Even more ice might be locked away in the deep subsurface.Carr, 2006, p. 173. The chemical signature of water vapor on Mars was first unequivocally demonstrated in 1963 by spectroscopy using an Earth-based telescope. In 2008 and 2013, ice was detected in soil samples taken by the Phoenix lander and ''Curiosity'' rover. In 2018, radar findings suggested the pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plan View Of Korolev Crater
A plan is typically any diagram or list of steps with details of timing and resources, used to achieve an Goal, objective to do something. It is commonly understood as a modal logic, temporal set (mathematics), set of intended actions through which one expects to achieve a goal. For space, spatial or Plane (geometry), planar topology, topologic or topography, topographic sets see map. Plans can be formal or informal: * Structured and formal plans, used by multiple people, are more likely to occur in projects, diplomacy, careers, economic development, military campaigns, combat, sports, games, or in the conduct of other business. In most cases, the absence of a well-laid plan can have adverse effects: for example, a non-robust project plan can cost the organization time and money. * Informal or ad hoc plans are created by individuals in all of their pursuits. The most popular ways to describe plans are by their breadth, time frame, and specificity; however, these planning clas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground-penetrating Radar
Ground-penetrating radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. It is a non-intrusive method of surveying the sub-surface to investigate underground utilities such as concrete, asphalt, metals, pipes, cables or masonry. This nondestructive method uses electromagnetic radiation in the microwave band ( UHF/ VHF frequencies) of the radio spectrum, and detects the reflected signals from subsurface structures. GPR can have applications in a variety of media, including rock, soil, ice, fresh water, pavements and structures. In the right conditions, practitioners can use GPR to detect subsurface objects, changes in material properties, and voids and cracks. GPR uses high-frequency (usually polarized) radio waves, usually in the range 10 MHz to 2.6 GHz. A GPR transmitter and antenna emits electromagnetic energy into the ground. When the energy encounters a buried object or a boundary between materials having different permittivities, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dry Lake
A dry lake bed, also known as a playa (), is a basin or depression that formerly contained a standing surface water body, which disappears when evaporation processes exceed recharge. If the floor of a dry lake is covered by deposits of alkaline compounds, it is known as an alkali flat. If covered with salt, it is known as a '' salt flat.'' Terminology If its basin is primarily salt, then a dry lake bed is called a '' salt pan'', ''pan'', or ''salt flat'' (the latter being a remnant of a salt lake). ''Hardpan'' is the dry terminus of an internally drained basin in a dry climate, a designation typically used in the Great Basin of the western United States. Another term for dry lake bed is ''playa''. The Spanish word ''playa'' () literally means "beach". Dry lakes are known by this name in some parts of Mexico and the western United States. This term is used e.g. on the Llano Estacado and other parts of the Southern High Plains and is commonly used to address paleolake sedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Delta
A river delta is a landform, archetypically triangular, created by the deposition of the sediments that are carried by the waters of a river, where the river merges with a body of slow-moving water or with a body of stagnant water. The creation of a river delta occurs at the '' river mouth'', where the river merges into an ocean, a sea, or an estuary, into a lake, a reservoir, or (more rarely) into another river that cannot carry away the sediment supplied by the feeding river. Etymologically, the term ''river delta'' derives from the triangular shape (Δ) of the uppercase Greek letter delta. In hydrology, the dimensions of a river delta are determined by the balance between the watershed processes that supply sediment and the watershed processes that redistribute, sequester, and export the supplied sediment into the receiving basin. River deltas are important in human civilization, as they are major agricultural production centers and population centers. They can provide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valley Networks (Mars)
Valley networks are branching networks of valleys on Mars that superficially resemble terrestrial river drainage basins.Carr, M.H. (2006), The Surface of Mars. Cambridge Planetary Science Series, Cambridge University Press. They are found mainly erosion, incised into the terrain of the martian Geology of Mars#Hemispheric dichotomy, southern highlands, and are typically - though not always - of Noachian age (approximately four billion years old). The individual valleys are typically less than 5 kilometers wide, though they may extend for up to hundreds or even thousands of kilometers across the martian surface. The form, distribution, and implied evolution of the valley networks are of great importance for what they may tell us about the history of liquid water on Mars, water on the martian surface, and hence Mars' climate history. Some authors have argued that the properties of the networks demand that a hydrological cycle must have been active on ancient Mars,Craddock, R.A., and H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outflow Channels
Outflow channels are extremely long, wide swathes of scoured ground on Mars.Carr, M.H. (2006), ''The Surface of Mars''. Cambridge Planetary Science Series, Cambridge University Press. They extend many hundreds of kilometers in length and are typically greater than one kilometer in width. They are thought to have been carved by huge outburst floods. Crater counts indicate that most of the channels were cut since the early Hesperian,Hartmann, W.K., and Neukum, G. (2001). "Cratering chronology and the evolution of Mars". In: ''Chronology and Evolution of Mars'', ed. R. Kallenbach et al. Dordrecht: Kluwer, p. 165-94. though the age of the features is variable between different regions of Mars. Some outflow channels in the Amazonis and Elysium Planitiae regions have yielded ages of only tens of millions of years, extremely young by the standards of Martian topographic features.Burr, D.M., McEwan, A.S., and Sakimoto, S.E. (2002). "Recent aqueous floods from the Cerberus Fossae", ''M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'' is the peer review, peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' cover the full range of List of academ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The New York Times
''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of the longest-running newspapers in the United States, the ''Times'' serves as one of the country's Newspaper of record, newspapers of record. , ''The New York Times'' had 9.13 million total and 8.83 million online subscribers, both by significant margins the List of newspapers in the United States, highest numbers for any newspaper in the United States; the total also included 296,330 print subscribers, making the ''Times'' the second-largest newspaper by print circulation in the United States, following ''The Wall Street Journal'', also based in New York City. ''The New York Times'' is published by the New York Times Company; since 1896, the company has been chaired by the Ochs-Sulzberger family, whose current chairman and the paper's publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbial Life
A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in Jain literature authored in 6th-century BC India. The scientific study of microorganisms began with their observation under the microscope in the 1670s by Anton van Leeuwenhoek. In the 1850s, Louis Pasteur found that microorganisms caused food spoilage, debunking the theory of spontaneous generation. In the 1880s, Robert Koch discovered that microorganisms caused the diseases tuberculosis, cholera, diphtheria, and anthrax. Microorganisms are extremely diverse, representing most unicellular organisms in all three domains of life: two of the three domains, Archaea and Bacteria, only contain microorganisms. The third domain, Eukaryota, includes all multicellular o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Lake
A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from the ocean, although they may be connected with the ocean by rivers. Lakes, as with other bodies of water, are part of the water cycle, the processes by which water moves around the Earth. Most lakes are fresh water and account for almost all the world's surface freshwater, but some are salt lakes with salinities even higher than that of seawater. Lakes vary significantly in surface area and volume of water. Lakes are typically larger and deeper than ponds, which are also water-filled basins on land, although there are no official definitions or scientific criteria distinguishing the two. Lakes are also distinct from lagoons, which are generally shallow tidal pools dammed by sandbars or other material at coastal regions of oceans or large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gale (crater)
Gale is a crater, and probable dry lake, at in the northwestern part of the Aeolis quadrangle on Mars. It is in diameter and estimated to be about 3.5–3.8 billion years old. The crater was named after Walter Frederick Gale, an amateur astronomer from Sydney, Australia, who observed Mars in the late 19th century. Aeolis Mons, also known as Mount Sharp, is a mountain in the center of Gale and rises high. Aeolis Palus is the plain between the northern wall of Gale and the northern foothills of Aeolis Mons. Peace Vallis, a nearby outflow channel, 'flows' down from the hills to the Aeolis Palus below and seems to have been carved by flowing water. Several lines of evidence suggest that a lake existed inside Gale shortly after the formation of the crater. The NASA Mars rover ''Curiosity'', of the Mars Science Laboratory (MSL) mission, landed in "Yellowknife" ''Quad 51'' of Aeolis Palus in Gale at 05:32 UTC August 6, 2012. NASA named the landing location Bradbury Landi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeolis Palus
Aeolis Palus is a plain between the northern wall of Gale crater and the northern foothills of Aeolis Mons (Mount Sharp) on Mars. It is located at . The NASA Mars Science Laboratory mission landed the ''Curiosity'' rover on Aeolis Palus in August 2012. ''Curiosity'' spent two (Earth) years exploring the plain as it drove towards Aeolis Mons. The rover left the plain in September 2014 when it reached the mountain's foothills. Spacecraft exploration On August 5, 2012, at 10:32 p.m. PDT/mission time (August 6, 2012, at 5:32 UTC), mission control at JPL received a signal from the NASA ''Curiosity'' rover that it had successfully landed in "Yellowknife" ''Quad 51'' of ''Aeolis Palus''. The rover's mission is to explore the surface area of Gale Crater focusing first near its landing site on ''Aeolis Palus'' and then venturing into the nearby foothills of Aeolis Mons (unofficially, "Mount Sharp") to investigate its geological features and strata. On September 26, 2013, NASA sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
