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Volcanism
Volcanism, vulcanism, volcanicity, or volcanic activity is the phenomenon where solids, liquids, gases, and their mixtures erupt to the surface of a solid-surface astronomical body such as a planet or a moon. It is caused by the presence of a heat source, usually internally generated, inside the body; the heat is generated by various processes, such as radioactive decay or tidal heating. This heat partially melts solid material in the body or turns material into gas. The mobilized material rises through the body's interior and may break through the solid surface. Causes For volcanism to occur, the temperature of the mantle must have risen to about half its melting point. At this point, the mantle's viscosity will have dropped to about 1021 Pascal-seconds. When large scale melting occurs, the viscosity rapidly falls to 103 Pascal-seconds or even less, increasing the heat transport rate a million-fold. The occurrence of volcanism is partially due to the fact that melted materi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryovolcanism
A cryovolcano (sometimes informally referred to as an ice volcano) is a type of volcano that erupts gases and volatile material such as liquid water, ammonia, and hydrocarbons. The erupted material is collectively referred to as ''cryolava''; it originates from a reservoir of subsurface ''cryomagma''. Cryovolcanic eruptions can take many forms, such as fissure and curtain eruptions, effusive cryolava flows, and large-scale resurfacing, and can vary greatly in output volumes. Immediately after an eruption, cryolava quickly freezes, constructing geological features and altering the surface. Although rare in the inner Solar System, past and recent cryovolcanism is common on planetary objects in the outer Solar System, especially on the icy moons of the giant planets and potentially amongst the dwarf planets as well. As such, cryovolcanism is important to the geological histories of these worlds, constructing landforms or even resurfacing entire regions. Despite this, only a few ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar day) that is synchronized to its orbital period (Lunar month#Synodic month, lunar month) of 29.5 Earth days. This is the product of Earth's gravitation having tidal forces, tidally pulled on the Moon until one part of it stopped rotating away from the near side of the Moon, near side, making always the same lunar surface face Earth. Conversley, the gravitational pull of the Moon, on Earth, is the main driver of Earth's tides. In geophysical definition of planet, geophysical terms, the Moon is a planetary-mass object or satellite planet. Its mass is 1.2% that of the Earth, and its diameter is , roughly one-quarter of Earth's (about as wide as the contiguous United States). Within the Solar System, it is the List of Solar System objects by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Io (moon)
Io () is the innermost and second-smallest of the four Galilean moons of the planet Jupiter. Slightly larger than Earth's Moon, Io is the list of natural satellites, fourth-largest natural satellite in the Solar System, has the highest density of any natural satellite, the strongest surface gravity of any natural satellite, and the lowest amount of water by atomic ratio of any known astronomical object in the Solar System. With over 400 active volcanoes, Io is the most geologically active object in the Solar System. This extreme geologic activity results from Tidal heating of Io, tidal heating from friction generated within Io's interior as it is pulled between Jupiter and the other Galilean moons—Europa (moon), Europa, Ganymede (moon), Ganymede, and Callisto (moon), Callisto. Several volcanoes produce plumes of sulfur and sulfur dioxide as high as above the surface. Io's surface is also dotted with more than 100 mountains uplifted by extensive compression at the base of Io' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Event
An impact event is a collision between astronomical objects causing measurable effects. Impact events have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effect. When large objects impact terrestrial planets such as the Earth, there can be significant physical and Biosphere, biospheric consequences, as the impacting body is usually traveling at several kilometres per second (km/s), with a minimum impact speed of 11.2 km/s (7.0 mi/s) for bodies striking Earth. Atmosphere, While planetary atmospheres can mitigate some of these impacts through the effects of atmospheric entry, many large bodies retain sufficient energy to reach the surface and cause substantial damage. This results in the formation of Impact crater, impact craters and Impact structure, structures, shaping the dominant landforms found across various types of solid objects found in the Solar System. Their prevalence and ubiquity pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triton (moon)
Triton is the largest natural satellite of the planet Neptune. It is the only moon of Neptune massive enough to be list of gravitationally rounded objects of the Solar System, rounded under its own gravity and hosts a atmosphere of Triton, thin, hazy atmosphere. Triton orbits Neptune in a retrograde orbit—revolving in the opposite direction to the parent planet's rotation—the only large moon in the Solar System to do so. Triton is thought to have once been a dwarf planet from the Kuiper belt, gravitational capture, captured into Neptune's orbit by the latter's gravity. At in diameter, Triton is the list of natural satellites#List, seventh-largest moon in the Solar System, the second-largest planetary moon in relation to its primary (after Earth's Moon), and larger than all of the known dwarf planets. The mean density is , reflecting a composition of approximately 30–45% ice, water ice by mass, with the rest being mostly rock and metal. Triton is differentiated, with a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Internal Heat Budget
Earth's internal heat budget is fundamental to the thermal history of the Earth. The flow of heat from Earth's interior to the surface is estimated at 47±2 terawatts (TW) and comes from two main sources in roughly equal amounts: the ''radiogenic heat'' produced by the radioactive decay of isotopes in the mantle and crust, and the ''primordial heat'' left over from the formation of Earth. Earth's internal heat travels along geothermal gradients and powers most geological processes. It drives mantle convection, plate tectonics, mountain building, rock metamorphism, and volcanism. Convective heat transfer within the planet's high-temperature metallic core is also theorized to sustain a geodynamo which generates Earth's magnetic field. Despite its geological significance, Earth's interior heat contributes only 0.03% of Earth's total energy budget at the surface, which is dominated by 173,000 TW of incoming solar radiation. This external energy source powers most of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magmatism And Volcanism EN
Magmatism is the emplacement of magma within and at the surface of the outer layers of a terrestrial planet, which solidifies as igneous rocks. It does so through magmatic activity or igneous activity, the production, intrusion and extrusion of magma or lava. Volcanism is the surface expression of magmatism. Magmatism is one of the main processes responsible for mountain formation. The nature of magmatism depends on the tectonic setting. For example, andesitic magmatism is associated with the formation of island arcs at convergent plate boundaries while basaltic magmatism is found at mid-ocean ridges during sea-floor spreading at divergent plate boundaries. On Earth, magma forms by partial melting of silicate rocks either in the mantle, continental or oceanic crust. Evidence for magmatic activity is usually found in the form of igneous rocks formed from magma. Convergent boundaries Magmatism is associated with all stages of the development of convergent plate boundaries, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chicxulub Crater
The Chicxulub crater is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is offshore, but the crater is named after the onshore community of Chicxulub Pueblo (not the larger coastal town of Chicxulub Puerto). It was formed slightly over 66 million years ago when an asteroid, about in diameter, struck Earth. The crater is estimated to be in diameter and in depth. It is believed to be the second largest impact structure on Earth, and the only one whose peak ring is intact and directly accessible for scientific research. The crater was discovered by Antonio Camargo and Glen Penfield, geophysicists who had been looking for petroleum in the Yucatán Peninsula during the late 1970s. Penfield was initially unable to obtain evidence that the geological feature was a crater and gave up his search. Later, through contact with Alan R. Hildebrand in 1990, Penfield obtained samples that suggested it was an impact feature. Evidence for the crater's imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decompression Melting
Igneous rock ( ), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava. The magma can be derived from partial melts of existing rocks in either a planet's mantle or crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms, orogens, basins, large igneous provinces, extended crust and oceanic crust. Geological significance Igneous and metamorphic rocks make up 90–95% of the top of the Earth's crust by volume. Igneous rocks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Satellite
A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body (or sometimes another natural satellite). Natural satellites are colloquially referred to as moons, a derivation from the Moon of Earth. In the Solar System, there are six planetary satellite systems containing 418 known natural satellites altogether. Seven objects commonly considered dwarf planets by astronomers are also known to have natural satellites: , Pluto, Haumea, , Makemake, , and Eris. As of January 2022, there are 447 other minor planets known to have natural satellites. A planet usually has at least around 10,000 times the mass of any natural satellites that orbit it, with a correspondingly much larger diameter. The Earth–Moon system is a unique exception in the Solar System; at 3,474 kilometres (2,158 miles) across, the Moon is 0.273 times the diameter of Earth and about of its mass. The next largest ratios are the N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tidal Heating
Tidal heating (also known as tidal working or tidal flexing) occurs through the tidal friction processes: orbital and rotational energy is dissipated as heat in either (or both) the surface ocean or interior of a planet or satellite. When an object is in an elliptical orbit, the tidal forces acting on it are stronger near periapsis than near apoapsis. Thus the deformation of the body due to tidal forces (i.e. the tidal bulge) varies over the course of its orbit, generating internal friction which heats its interior. This energy gained by the object comes from its orbital energy and/or rotational energy, so over time in a two-body system, the initial elliptical orbit decays into a circular orbit ( tidal circularization) and the rotational periods of the two bodies adjust towards matching the orbital period (tidal locking). Sustained tidal heating occurs when the elliptical orbit is prevented from circularizing due to additional gravitational forces from other bodies that keep tug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Geographic Society
The National Geographic Society, headquartered in Washington, D.C., United States, is one of the largest nonprofit scientific and educational organizations in the world. Founded in 1888, its interests include geography, archaeology, natural science, the promotion of environmental protection, environmental and historical preservation, historical conservation movement, conservation, and the study of civilization, world culture and World history (field), history. The National Geographic Society's logo is a yellow page orientation, portrait frame—rectangular in shape—which appears on the Margin (typography), margins surrounding the front covers of its magazines and as its television channel logo. Through National Geographic Partners (a joint venture with The Walt Disney Company), the Society operates the National Geographic, magazine, National Geographic Global Networks, TV channels, a website, worldwide events, and other media operations. Overview The National Geographic S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
