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Volcanic Ejecta
Ejecta (from the Latin: "things thrown out", singular ejectum) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic materials (tephra) that came out of a volcanic explosion and magma eruption volcanic vent, or crater, has traveled through the air or under water, and fell back on the ground surface or on the ocean floor. Volcanology Typically in volcanology, ejecta is a result of explosive eruptions. In an explosive eruption, large amounts of gas are dissolved in extremely viscous lava; this lava froths to the surface until the material is expelled rapidly due to the trapped pressure. Sometimes in such an event a lava plug or volcanic neck forms from lava that solidifies inside a volcano's vent, causing heat and pressure to build up to an extreme with no way to escape. When the blockage breaks and cannot sustain itself any longer, a more violent eruption occurs, which allows materials to be ejected out of the vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Bomb
A volcanic bomb or lava bomb is a mass of partially molten rock (tephra) larger than 64 mm (2.5 inches) in diameter, formed when a volcano ejects viscous fragments of lava during an eruption. Because volcanic bombs cool after they leave the volcano, they are extrusive igneous rocks. Volcanic bombs can be thrown many kilometres from an erupting vent, and often acquire aerodynamic shapes during their flight. Bombs can be extremely large; the 1935 eruption of Mount Asama in Japan expelled bombs measuring 5–6 m (16-20 ft) in diameter up to from the vent. Volcanic bombs are a significant volcanic hazard, and can cause severe injuries and death to people in an eruption zone. One such incident occurred at Galeras volcano in Colombia in 1993; six people near the summit were killed and several seriously injured by lava bombs when the volcano erupted unexpectedly. On July 16, 2018, 23 people were injured on a tour boat near the Kilauea volcano as a result of a basketb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operation Plumbbob
Operation Plumbbob was a series of nuclear tests that were conducted between May 28 and October 7, 1957, at the Nevada Test Site, following ''Project 57'', and preceding '' Project 58/58A''. Background The operation consisted of 29 explosions, of which only two did not produce any nuclear yield. Twenty-one laboratories and government agencies were involved. While most ''Operation Plumbbob'' tests contributed to the development of warheads for intercontinental and intermediate range missiles, they also tested air defense and anti-submarine warheads with smaller yields. They included forty-three military effects tests on civil and military structures, radiation and bio-medical studies, and aircraft structural tests. ''Operation Plumbbob'' had the tallest tower tests to date in the U.S. nuclear testing program as well as high-altitude balloon tests. One nuclear test involved the largest troop maneuver ever associated with U.S. nuclear testing. Approximately 18,000 members of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Launch System
A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch control center, launch control center and systems such as vehicle assembly and fueling. Launch vehicles are engineered with advanced aerodynamics and technologies, which contribute to large operating costs. An orbital spaceflight, orbital launch vehicle must lift its payload at least to the boundary of space, approximately and accelerate it to a horizontal velocity of at least . Suborbital spaceflight, Suborbital vehicles launch their payloads to lower velocity or are launched at elevation angles greater than horizontal. Practical orbital launch vehicles are multistage rockets which use chemical propellants such as Solid-propellant rocket, solid fuel, liquid hydrogen, kerosene, liquid oxygen, or Hypergolic propellants. Launch vehicles are cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronal Mass Ejection
A coronal mass ejection (CME) is a significant release of plasma and accompanying magnetic field from the Sun's corona into the heliosphere. CMEs are often associated with solar flares and other forms of solar activity, but a broadly accepted theoretical understanding of these relationships has not been established. If a CME enters interplanetary space, it is referred to as an interplanetary coronal mass ejection (ICME). ICMEs are capable of reaching and colliding with Earth's magnetosphere, where they can cause geomagnetic storms, aurorae, and in rare cases damage to electrical power grids. The largest recorded geomagnetic perturbation, resulting presumably from a CME, was the solar storm of 1859. Also known as the Carrington Event, it disabled parts of the at the time newly created United States telegraph network, starting fires and shocking some telegraph operators. Near solar maxima, the Sun produces about three CMEs every day, whereas near solar minima, there is about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova
A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or when a white dwarf is triggered into runaway nuclear fusion. The original object, called the ''progenitor'', either collapses to a neutron star or black hole, or is completely destroyed. The peak optical luminosity of a supernova can be comparable to that of an entire galaxy before fading over several weeks or months. Supernovae are more energetic than novae. In Latin language, Latin, ''nova'' means "new", referring astronomically to what appears to be a temporary new bright star. Adding the prefix "super-" distinguishes supernovae from ordinary novae, which are far less luminous. The word ''supernova'' was coined by Walter Baade and Fritz Zwicky in 1929. The last supernova to be directly observed in the Milky Way was Kepler's Supernova in 160 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliophysics
Heliophysics (from the prefix " helio", from Attic Greek ''hḗlios'', meaning Sun, and the noun "physics": the science of matter and energy and their interactions) is the physics of the Sun and its connection with the Solar System. NASA defines heliophysics as "(1) the comprehensive new term for the science of the Sun - Solar System Connection, (2) the exploration, discovery, and understanding of Earth's space environment, and (3) the system science that unites all of the linked phenomena in the region of the cosmos influenced by a star like our Sun." Heliophysics concentrates on the Sun's effects on Earth and other bodies within the Solar System, as well as the changing conditions in space. It is primarily concerned with the magnetosphere, ionosphere, thermosphere, mesosphere, and upper atmosphere of the Earth and other planets. Heliophysics combines the science of the Sun, corona, heliosphere and geospace, and encompasses a wide variety of astronomical phenomena, including ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrophysics
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline said, Astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–''what'' they are, rather than ''where'' they are." Among the subjects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, ''astrophysicists'' apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is gone. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a Volcanic crater, crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century. Only seven caldera-forming collapses are known to have occurred between 1911 and 2016. More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018. Etymology The term ''caldera'' comes from Spanish language, S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eden Patera
Eden Patera is a feature located in the Mare Acidalium quadrangle on the planet Mars. In October 2013 the feature gained some attention when it was speculated it may be a supervolcano rather than an impact crater, according to research from the Planetary Science Institute in Tucson, led by Joseph R. Michalski. NASA, Oct. 22, 2013 The research postulated the crater was formed by the volcano's collapsing, rather than from an impact. Some of the reasons for suspecting that Eden Patera is a collapsed caldera rather than an impact crater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terrestrial planet with a thin atmosphere (less than 1% that of Earth's), and has a crust primarily composed of elements similar to Earth's crust, as well as a core made of iron and nickel. Mars has surface features such as impact craters, valleys, dunes and polar ice caps. It has two small and irregularly shaped moons, Phobos (moon), Phobos and Deimos (moon), Deimos. Some of the most notable surface features on Mars include Olympus Mons, the largest volcano and List of tallest mountains in the Solar System, highest known mountain in the Solar System and Valles Marineris, one of the largest canyons in the Solar System. The North Polar Basin (Mars), Borealis basin in the Northern Hemisphere covers approximately 40% of the planet and may be a la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ejecta Blanket
An ejecta blanket is a generally symmetrical apron of ejecta that surrounds an impact crater; it is layered thickly at the crater's rim and thin to discontinuous at the blanket's outer edge. The impact cratering is one of the basic surface formation mechanisms of the solar system bodies (including the Earth) and the formation and emplacement of ejecta blankets are the fundamental characteristics associated with impact cratering event. The ejecta materials are considered as the transported materials beyond the transient cavity formed during impact cratering regardless of the state of the target materials. Formation A blanket of ejecta is formed during the formation of meteor impact cratering and is composed usually of the materials of that are ejected from the cratering process. Ejecta materials are deposited on the preexisting layer of target materials and therefore it form an inverted stratigraphy than the underlying bedrock. In some cases, the excavated fragment of ejects ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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