|
Mena (Mercurian Crater)
Mena is a crater in the Beethoven quadrangle on Mercury. Its name was adopted by the International Astronomical Union in 1976. Mena is named for the Spanish poet Juan de Mena, who lived from 1411 to 1456. Mena lies on the eastern rim of a larger unnamed crater, which is in turn within the much larger crater Vieira da Silva. Crater Type and Features Situated on the rim of an older, larger crater, Mena does not take on the typical bowl shape created by smaller impacts. Instead, Mena is classified as a complex crater with a peak located inside the bowl-shaped cavity. This peak is caused by a propagating shock wave In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a med ... that rebounds and converges at the crater's center, causing the target material to be uplifted. Typically, the prese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MESSENGER
''MESSENGER'' was a NASA robotic space probe that orbited the planet Mercury between 2011 and 2015, studying Mercury's chemical composition, geology, and magnetic field. The name is a backronym for "Mercury Surface, Space Environment, Geochemistry, and Ranging", and a reference to the messenger god Mercury from Roman mythology. ''MESSENGER'' was launched aboard a Delta II rocket in August 2004. Its path involved a complex series of flybys – the spacecraft flew by Earth once, Venus twice, and Mercury itself three times, allowing it to decelerate relative to Mercury using minimal fuel. During its first flyby of Mercury in January 2008, ''MESSENGER'' became the second mission, after Mariner 10 in 1975, to reach Mercury. ''MESSENGER'' entered orbit around Mercury on March 18, 2011, becoming the first spacecraft to do so. It successfully completed its primary mission in 2012. Following two mission extensions, the spacecraft used the last of its maneuvering propellant to deo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mariner 10
''Mariner 10'' was an American Robotic spacecraft, robotic space probe launched by NASA on 3 November 1973, to fly by the planets Mercury (planet), Mercury and Venus. It was the first spacecraft to perform flybys of multiple planets. ''Mariner 10'' was launched approximately two years after ''Mariner 9'' and was the last spacecraft in the Mariner program. (Mariner 11 and Mariner 12 were allocated to the Voyager program and redesignated ''Voyager 1'' and ''Voyager 2''.) The mission objectives were to measure Mercury's environment, atmosphere, surface, and body characteristics and to make similar investigations of Venus. Secondary objectives were to perform experiments in the interplanetary medium and to obtain experience with a dual-planet gravity assist mission. ''Mariner 10''s science team was led by Bruce C. Murray at the Jet Propulsion Laboratory. Design and trajectory ''Mariner 10'' was the first spacecraft to make use of an interplanetary gravitational slingshot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juan De Mena
Juan de Mena (1411–1456) was one of the most significant Spanish poets of the fifteenth century. He was highly regarded at the court of Juan II de Castilla, who appointed him ''veinticuatro'' (one of twenty-four aldermen) of Córdoba, ''secretario de cartas latinas'' (secretary of Latin letters) and ''cronista real'' (royal chronicler). His works show the influence of Renaissance humanism and place him in the period of transition in Spain from the Middle Ages to the Renaissance. Biographical Information There is scant evidence about the early part of Mena’s life, but most modern scholars agree that he was born at Córdoba, Spain, his father died shortly after his birth, and his mother a few years later. He was likely the second of two sons and was related to a former ''veinticuatro'' of Córdoba, although it is unclear how. ''Memorias de algunos linages'' (An Account of Some Lineages), attributed to Mena, claims that his family came from the valley of Mena in La Montaña, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mena Crater EW0229581356I Web Crop
MENA, an acronym in the English language, refers to a grouping of countries situated in and around the Middle East and North Africa. It is also known as WANA, SWANA, or NAWA, which alternatively refers to the Middle East as Western Asia (or as "Southwestern Asia" in the case of "SWANA") and is a way to refer to the geography instead of the political term. As a regional identifier, ''MENA'' is often used in academia, military planning, disaster relief, media planning (as a broadcast region), and business writing. Moreover, the region shares a number of cultural, economic, and environmental similarities across its comprising countries; for example, some of the most extreme impacts of climate change will be felt in MENA. Some terms have a wider definition than MENA, such as MENASA, MENAP or Greater Middle East, which extends to South Asia to include the countries of Afghanistan and Pakistan. The term MENAT explicitly includes Turkey, which is usually excluded from some MENA de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beethoven Quadrangle
The Beethoven quadrangle is located in the equatorial region of Mercury, in the center of the area imaged by ''Mariner 10''. Most pictures of the quadrangle were obtained at high sun angles as the ''Mariner 10'' spacecraft receded from the planet. Geologic map units are described and classified on the basis of morphology, texture, and albedo, and they are assigned relative ages based on stratigraphic relations and on visual comparisons of the density of superposed craters. Crater ages are established by relative freshness of appearance, as indicated by topographic sharpness of their rim crests and degree of preservation of interior and exterior features such as crater floors, walls, and ejecta aprons. Generally, topography appears highly subdued because of the sun angle, and boundaries between map units are not clearly defined. Impact craters larger than about 250 km are referred to as basins. Unlike many basins on the Moon, however, the two obvious basins in the quadrangl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury (planet)
Mercury is the smallest planet in the Solar System and the closest to the Sun. Its orbit around the Sun takes 87.97 Earth days, the shortest of all the Sun's planets. It is named after the Roman god ' ( Mercury), god of commerce, messenger of the gods, and mediator between gods and mortals, corresponding to the Greek god Hermes (). Like Venus, Mercury orbits the Sun within Earth's orbit as an inferior planet, and its apparent distance from the Sun as viewed from Earth never exceeds 28°. This proximity to the Sun means the planet can only be seen near the western horizon after sunset or the eastern horizon before sunrise, usually in twilight. At this time, it may appear as a bright star-like object, but is more difficult to observe than Venus. From Earth, the planet telescopically displays the complete range of phases, similar to Venus and the Moon, which recurs over its synodic period of approximately 116 days. The synodic proximity of Mercury to Earth makes Mercury most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Institute Of Physics Publishing
IOP Publishing (previously Institute of Physics Publishing) is the publishing company of the Institute of Physics. It provides publications through which scientific research is distributed worldwide, including journals, community websites, magazines, conference proceedings and books. The Institute of Physics is a scientific charity devoted to increasing the practice, understanding and application of physics. Any financial surplus earned by IOP Publishing goes to support physics through the activities of the Institute. The main IOP Publishing headquarters is located in Bristol, England, and the North American headquarters is in Philadelphia, United States. It also has regional offices in, Mexico City, Beijing, Tokyo, Moscow, St. Petersburg, and Sydney. It employs over 400 staff. It was the first physics publisher to publish a journal on the internet. In 1994, the journal ''Classical and Quantum Gravity'' was published as a TeX file. In January 1996 the organization launched the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded in 1919 and is based in Paris, France. The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. As of 2018, the Union had over 13,700 individual members, spanning 90 countries, and 82 national members. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vieira Da Silva (crater)
Vieira da Silva is a large crater on Mercury. Its name was adopted by the International Astronomical Union (IAU) in 2013. The crater is named for the Portuguese abstract painter Maria Helena Vieira da Silva. The small, rayed crater Mena lies within Vieira da Silva. To the west are Thoreau and Lysippus Lysippos (; grc-gre, Λύσιππος) was a Greek sculptor of the 4th century BC. Together with Scopas and Praxiteles, he is considered one of the three greatest sculptors of the Classical Greek era, bringing transition into the Hellenistic p ... craters. References {{Mercury (planet) Impact craters on Mercury ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complex Crater
Complex craters are a type of large impact crater morphology. Above a certain threshold size, which varies with planetary gravity, the collapse and modification of the transient cavity is much more extensive, and the resulting structure is called a ''complex crater''. The collapse of the transient cavity is driven by gravity, and involves both the uplift of the central region and the inward collapse of the rim. The central uplift is not the result of ''elastic rebound'' which is a process in which a material with elastic strength attempts to return to its original geometry; rather the uplift is a process in which a material with little or no strength attempts to return to a state of gravitational equilibrium. Complex craters have uplifted centers, and they have typically broad flat shallow crater floors, and terraced walls. At the largest sizes, one or more exterior or interior rings may appear, and the structure may be labeled an ''impact basin'' rather than an impact crater. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance. When a shock wave passes through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Mercury (planet)")
