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Maat Mons
Maat Mons is a massive shield volcano on the planet Venus and the planet's second-highest mountain and highest volcano. It rises above the mean planetary radius at , and nearly 5 km above the surrounding plains. It is named after the Egyptian goddess of truth and justice, Ma'at. Structure Maat Mons has a large summit caldera, 28×31 km in size. Within the large caldera, there are at least five smaller collapse craters, up to 10 km in diameter. A chain of small craters 3–5 km in diameter extends some 40 km along the southeast flank of the volcano, but rather than indicating a large fissure eruption, they seem to also be formed by collapse: full resolution imagery from the ''Magellan'' probe reveals no evidence of lava flows from these craters. At least two large scale structural collapse events seem to have occurred in the past on Maat Mons. Activity Radar sounding by ''Magellan'' probe revealed evidence for comparatively recent volcanic activity a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magellan Probe
The ''Magellan'' spacecraft was a robotic space probe launched by NASA of the United States, on May 4, 1989, to map the surface of Venus by using synthetic-aperture radar and to measure the planetary gravitational field. The ''Magellan'' probe was the first interplanetary mission to be launched from the Space Shuttle, the first one to use the Inertial Upper Stage booster, and the first spacecraft to test aerobraking as a method for circularizing its orbit. ''Magellan'' was the fifth successful NASA mission to Venus, and it ended an eleven-year gap in U.S. interplanetary probe launches. History Beginning in the late 1970s, scientists advocated for a radar mapping mission to Venus. They first sought to construct a spacecraft named the '' Venus Orbiting Imaging Radar'' (VOIR), but it became clear that the mission would be beyond the budget constraints during the ensuing years. The VOIR mission was canceled in 1982. A simplified radar mission proposal was recommended by the So ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ash Flow
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of but is capable of reaching speeds up to . The gases and tephra can reach temperatures of about . Pyroclastic flows are the most deadly of all volcanic hazards and are produced as a result of certain explosive eruptions; they normally touch the ground and hurtle downhill, or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope. Origin of term The word ''pyroclast'' is derived from the Greek (''pýr''), meaning "fire", and (''klastós''), meaning "broken in pieces". A name for pyroclastic flows which glow red in the dark is (French, "burning cloud"); this was notably used to describe the disastrous 1902 eruption of Mount Pelée on Martinique, a Frenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of Venus
The surface of Venus is dominated by volcanic features and has more volcanoes than any other planet in the Solar System. It has a surface that is 90% basalt, and about 65% of the planet consists of a mosaic of volcanic lava plains, indicating that volcanism played a major role in shaping its surface. There are more than 1,000 volcanic structures and possible periodic resurfacing of Venus by floods of lava. The planet may have had a major global resurfacing event about 500 million years ago, from what scientists can tell from the density of impact craters on the surface. Venus has an atmosphere rich in carbon dioxide, with a density that is 90 times that of Earth's atmosphere. Even though there are over 1,600 major volcanoes on Venus, none are known to be erupting at present and most are probably long extinct. However, radar sounding by the ''Magellan'' probe revealed evidence for comparatively recent volcanic activity at Venus's highest volcano Maat Mons, in the form of ash flows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Propulsion Lab
The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States. Founded in the 1930s by Caltech researchers, JPL is owned by NASA and managed by the nearby California Institute of Technology (Caltech). The laboratory's primary function is the construction and operation of planetary robotic spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating the NASA Deep Space Network. Among the laboratory's major active projects are the Mars 2020 mission, which includes the ''Perseverance'' rover and the '' Ingenuity'' Mars helicopter; the Mars Science Laboratory mission, including the ''Curiosity'' rover; the InSight lander (''Interior Exploration using Seismic Investigations, Geodesy and Heat Transport''); the ''Mars Reconnaissance Orbiter''; the '' Juno'' spacecraft orbiting Jupiter; the ''SMAP'' satellite for earth surface s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanism On Venus
The surface of Venus is dominated by volcanic features and has more volcanoes than any other planet in the Solar System. It has a surface that is 90% basalt, and about 65% of the planet consists of a mosaic of volcanic lava plains, indicating that volcanism played a major role in shaping its surface. There are more than 1,000 volcanic structures and possible periodic resurfacing of Venus by floods of lava. The planet may have had a major global resurfacing event about 500 million years ago, from what scientists can tell from the density of impact craters on the surface. Venus has an atmosphere rich in carbon dioxide, with a density that is 90 times that of Earth's atmosphere. Even though there are over 1,600 major volcanoes on Venus, none are known to be erupting at present and most are probably long extinct. However, radar sounding by the '' Magellan'' probe revealed evidence for comparatively recent volcanic activity at Venus's highest volcano Maat Mons, in the form of ash flows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Montes On Venus
This is a list of montes (mountains, singular ''mons'') on the planet Venus. Venusian mountains are all named after goddesses in the mythologies of various cultures, except for the Maxwell Montes. The four main mountain ranges of Venus are named Akna Montes, Danu Montes, Freyja Montes, and Maxwell Montes. These are found on Ishtar Terra. Mountain ranges are formed by the folding and buckling of a planet's crust. The mountain ranges of Venus, like those of the Earth, are characterized by many parallel folds and faults. The presence of mountain ranges on Venus may provide evidence that the planet's surface is in motion. Montes Key *DIAM — Longest dimension of feature in kilometres *AS — Approval status **(1) — Adopted by the International Astronomical Union (IAU) General Assembly **(2) — Working Group for Planetary System Nomenclature (WGPSN) approval **(3) — Dropped, no longer in use See also * List of coronae on Venus * List of craters on Venus * List of tallest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it poses technical challenges due to its gaseous state under normal conditions for temperature and pressure. Naturally occurring methane is found both below ground and under the seafloor and is formed by both geological and biological processes. The largest reservoir of methane is under the seafloor in the form of methane clathrates. When methane reaches the surface and the atmosphere, it is known as atmospheric methane. The Earth's atmospheric methane concentration has increased by about 150% since 1750, and it accounts for 20% of the total radiative forcing from all of the long-lived and globally mixed greenhouse gases. It has also been detected on other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Dioxide
Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic activity and is produced as a by-product of copper extraction and the burning of sulfur- bearing fossil fuels. Structure and bonding SO2 is a bent molecule with ''C''2v symmetry point group. A valence bond theory approach considering just ''s'' and ''p'' orbitals would describe the bonding in terms of resonance between two resonance structures. The sulfur–oxygen bond has a bond order of 1.5. There is support for this simple approach that does not invoke ''d'' orbital participation. In terms of electron-counting formalism, the sulfur atom has an oxidation state of +4 and a formal charge of +1. Occurrence Sulfur dioxide is found on Earth and exists in very small concentrations and in the atmosphere at about 1 ppm. On other p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pioneer Venus
The Pioneer Venus project was part of the Pioneer program consisting of two spacecraft, the Pioneer Venus Orbiter and the Pioneer Venus Multiprobe, launched to Venus in 1978. The program was managed by NASA's Ames Research Center. The Pioneer Venus Orbiter entered orbit around Venus on December 4, 1978, and performed observations to characterize the atmosphere and surface of Venus. It continued to transmit data until October 1992. The Pioneer Venus Multiprobe deployed four small probes into the Venusian atmosphere on December 9, 1978. All four probes transmitted data throughout their descent to the surface. One probe survived the landing and transmitted data from the surface for over an hour. Overview The Pioneer mission consisted of two components, launched separately: an orbiter and a multiprobe. Orbiter The orbiter was launched on May 20, 1978 on an Atlas-Centaur rocket. The orbiter's mass was . The Pioneer Venus Orbiter was inserted into an elliptical orbit around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestial Body Atmosphere
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere is the outer region of a star, which includes the layers above the opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules. The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%) and trace gases. Most organisms use oxygen for respiration; lightning and bacteria perform nitrogen fixation to produce ammonia that is used to make nucleotides and amino acids; plants, algae, and cyanobacteria use carbon dioxide for photosynthesis. The layered composition of the atmosphere minimises the harmful effects of sunlight, ultraviolet radiation, the solar wind, and cosmic rays to protect organisms from genetic damage. The current com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Geology
Planetary geology, alternatively known as astrogeology or exogeology, is a planetary science discipline concerned with the geology of the celestial bodies such as the planets and their moons, asteroids, comets, and meteorites. Although the geo- prefix typically indicates topics of or relating to Earth, planetary geology is named as such for historical and convenience reasons; due to the types of investigations involved, it is closely linked with Earth-based geology. These investigations are centered around the composition, structure, processes, and history of a planet. Planetary geology includes such topics as determining the properties and processes of the internal structure of the terrestrial planets, and also looks at planetary volcanism and surface processes such as impact craters, fluvial and aeolian processes. The structures and compositions of the giant planets and their moons are also examined, as is the make-up of the minor bodies of the Solar System, such as aster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
