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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] |
Prometheus (volcano)
Prometheus is an active volcano on Jupiter's Natural satellite, moon Io (moon), Io. It is located on Io's hemisphere facing away from Jupiter at . Description Prometheus consists of a volcanic pit named Prometheus Patera and a compound lava flow, all surrounded by reddish sulfur and circular, bright sulfur dioxide () volcanic plume deposits. The volcano was first observed in images acquired by the ''Voyager 1'' spacecraft in March 1979. Later that year, the International Astronomical Union named this feature after a Greek mythology, Greek fire god, Prometheus. Prometheus is the site of a volcanic eruption that has been ongoing since at least the ''Voyager 1'' encounter in 1979. Between the Voyager encounters and the first observations by ''Galileo (spacecraft), Galileo'', a flow field was emplaced. Later ''Galileo'' observations of this flow field revealed numerous small breakouts, particularly on the western end of the flow field. Prometheus is the site of two volcanic eru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galilean Moons
The Galilean moons (), or Galilean satellites, are the four largest moons of Jupiter. They are, in descending-size order, Ganymede (moon), Ganymede, Callisto (moon), Callisto, Io (moon), Io, and Europa (moon), Europa. They are the most apparent magnitude, readily visible Solar System objects after Saturn, the dimmest of the classical planets; though their closeness to bright Jupiter makes naked-eye observation very difficult, they are readily seen with common binoculars, even under night sky Bortle scale, conditions of high light pollution. The invention of the telescope allowed astronomers to discover the moons in 1610. Through this, they became the first Timeline of discovery of Solar System planets and their moons, Solar System objects discovered since humans have started tracking the classical planets, and the first objects to be found to orbit any planet beyond Earth. They are planetary-mass moons and among the List of Solar System objects by size, largest objects in the Sola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callisto (moon)
Callisto ( ) is the second-largest moon of Jupiter, after Ganymede. In the Solar System it is the third-largest moon after Ganymede and Saturn's largest moon Titan, and nearly as large as the smallest planet Mercury. Callisto is, with a diameter of , roughly a third larger than Earth's Moon and orbits Jupiter on average at a distance of , which is about five times further out than the Moon orbiting Earth. It is the outermost of the four large Galilean moons of Jupiter, which were discovered in 1610 with one of the first telescopes, and is today visible from Earth with common binoculars. The surface of Callisto is the oldest and most heavily cratered in the Solar System. Its surface is completely covered with impact craters. It does not show any signatures of subsurface processes such as plate tectonics or volcanism, with no signs that geological activity in general has ever occurred, and is thought to have evolved predominantly under the influence of impacts. Promine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganymede (moon)
Ganymede is a natural satellite of Jupiter and the List of Solar System objects by size, largest and most massive in the Solar System. Like Saturn's largest moon Titan (moon), Titan, it is larger than the planet Mercury (planet), Mercury, but has somewhat less surface gravity than Mercury, Io (moon), Io, or the Moon due to its lower density compared to the three. Ganymede orbits Jupiter in roughly seven days and is in a 1:2:4 orbital resonance with the moons Europa (moon), Europa and Io (moon), Io, respectively. Ganymede is composed of silicate, silicate rock and water substance, water in approximately equal proportions. It is a fully Planetary differentiation, differentiated body with an iron-rich, Planetary core, liquid metallic core, giving it the lowest moment of inertia factor of any solid body in the Solar System. Its Planetary oceanography, internal ocean potentially contains more water than all of Earth's oceans combined. Ganymede's magnetic field is probably created ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europa (moon)
Europa () is a moons of Jupiter, natural satellite (moon) of Jupiter. Being observable from Earth with common binoculars it is one of the four Galilean moons. As such it is a planetary-mass moon, the smallest and least massive orbiting Jupiter, and slightly smaller and less massive than Moon, Earth's. Europa is an icy moon, being of the three icy Galilean moons the closest orbiting Jupiter. As a result it is exhibiting a relatively young surface, driven by tidal heating. Probably having an iron–nickel alloy, iron–nickel core, it consists mainly of silicate rock, with a water-ice shell. It has a very thin atmosphere, composed primarily of oxygen. Its geologically young white-beige surface is Glacial striation, striated by light Tan (color), tan cracks and streaks, with very few impact craters. In addition to Earth-bound telescope observations, Europa has been examined by a succession of space-probe flybys, the first occurring in the early 1970s. In September 2022, the Juno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of the processes involved is called tribology, and has a history of more than 2000 years. Friction can have dramatic consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire. Another important consequence of many types of friction can be wear, which may lead to performance degradation or damage to components. It is known that frictional energy losses account for about 20% of the total energy expenditure of the world. As briefly discussed later, there are many different contributors to the retarding force in friction, ranging from asperity deformation to the generation of charges and changes in local structure. When two bodies in contact move relative to each other, due to these variou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tidal Heating Of Io
Tidal heating, or tidal working, occurs on the Galilean moon Io due to frictional processes caused by Jupiter’s gravitational pull. As Io orbits, the immense gravity of Jupiter exerts a stronger force on the side closest to the planet than on the opposite side, distorting Io’s shape. In addition, Io is in an orbital resonance with Europa and Ganymede, two of Jupiter’s other large moons. This interaction keeps Io’s orbit slightly elliptical, causing its distance from Jupiter to vary. As a result, the degree of gravitational distortion changes over time, flexing Io’s interior and generating heat through friction. This process drives Io’s intense volcanic activity, making it the most geologically active body in the Solar System. Although there is general agreement that the cause of the heat as manifested in Io's many volcanoes is tidal heating from the pull of gravity from Jupiter and its moon Europa, the volcanoes are not in the positions predicted with tidal heating. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes resulting from divergent tectonic activity are usually non-explosive whereas those resulting from convergent tectonic activity cause violent eruptions."Mid-ocean ridge tectonics, volcanism and geomorphology." Geology 26, no. 455 (2001): 458. https://macdonald.faculty.geol.ucsb.edu/papers/Macdonald%20Mid-Ocean%20Ridge%20Tectonics.pdf Volcanoes can also form where there is str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Object
An astronomical object, celestial object, stellar object or heavenly body is a naturally occurring physical entity, association, or structure that exists within the observable universe. In astronomy, the terms ''object'' and ''body'' are often used interchangeably. However, an astronomical body or celestial body is a single, tightly bound, contiguous entity, while an astronomical or celestial ''object'' is a complex, less cohesively bound structure, which may consist of multiple bodies or even other objects with substructures. Examples of astronomical objects include planetary systems, star clusters, nebulae, and galaxies, while asteroids, moons, planets, and stars are astronomical bodies. A comet may be identified as both a body and an object: It is a ''body'' when referring to the frozen nucleus of ice and dust, and an ''object'' when describing the entire comet with its diffuse coma and tail. History Astronomical objects such as stars, planets, nebulae, aster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Ratio
The atomic ratio is a measure of the ratio of atoms of one kind (i) to another kind (j). A closely related concept is the atomic percent (or at.%), which gives the percentage of one kind of atom relative to the total number of atoms. The molecular equivalents of these concepts are the molar fraction, or molar percent. Atoms Mathematically, the ''atomic percent'' is : \mathrm \ (\mathrm) = \frac \times 100 \ % where ''N''i are the number of atoms of interest and ''N''tot are the total number of atoms, while the ''atomic ratio'' is : \mathrm \ (\mathrm) = \mathrm \ (\mathrm) : \mathrm \ (\mathrm) \ . For example, the ''atomic percent'' of hydrogen in water (H2O) is , while the ''atomic ratio'' of hydrogen to oxygen is . Isotopes Another application is in radiochemistry, where this may refer to isotopic ratios or isotopic abundances. Mathematically, the ''isotopic abundance'' is : \mathrm \ (\mathrm) = \frac \ , where ''N''i are the number of atoms of the isotope of intere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Gravity
The surface gravity, ''g'', of an astronomical object is the gravitational acceleration experienced at its surface at the equator, including the effects of rotation. The surface gravity may be thought of as the acceleration due to gravity experienced by a hypothetical test particle which is very close to the object's surface and which, in order not to disturb the system, has negligible mass. For objects where the surface is deep in the atmosphere and the radius not known, the surface gravity is given at the 1 bar pressure level in the atmosphere. Surface gravity is measured in units of acceleration, which, in the SI system, are meters per second squared. It may also be expressed as a multiple of the Earth's standard surface gravity, which is equal to In astrophysics, the surface gravity may be expressed as , which is obtained by first expressing the gravity in cgs units, where the unit of acceleration and surface gravity is centimeters per second squared (cm/s2), and then t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar System" and "solar system" structures in theinaming guidelines document. The name is commonly rendered in lower case ('solar system'), as, for example, in the ''Oxford English Dictionary'' an''Merriam-Webster's 11th Collegiate Dictionary''. is the gravitationally bound Planetary system, system of the Sun and the objects that orbit it. It Formation and evolution of the Solar System, formed about 4.6 billion years ago when a dense region of a molecular cloud collapsed, forming the Sun and a protoplanetary disc. The Sun is a typical star that maintains a hydrostatic equilibrium, balanced equilibrium by the thermonuclear fusion, fusion of hydrogen into helium at its stellar core, core, releasing this energy from its outer photosphere. As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
