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Memphis Facula
Memphis Facula is a palimpsest, or "ghost crater", on Ganymede, the largest of the Jovian satellites. About 360 km across, it is situated in the southwestern part of Galileo Regio, a huge almost circular dark region in Ganymede's northern hemisphere. Although almost level today, it is a relic of a massive impact and once was a deep impact crater whose walls have slumped and its floor has risen isostatically, smoothing out the remaining topography with slush. The morphology of the larger palimpsests like Memphis Facula suggests that Ganymede's icy crust at the time of impact was about 10 km thick and was penetrated by the impact, allowing the slush and fluid beneath to fill and level out the crater. See also *Ganymede City ''3001: The Final Odyssey'' is a 1997 science fiction novel by British writer Arthur C. Clarke. It is the fourth and final book in Clarke's ''Space Odyssey'' series. Plot summary The novel begins with a brief prologue describing th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memphis Facula
Memphis Facula is a palimpsest, or "ghost crater", on Ganymede, the largest of the Jovian satellites. About 360 km across, it is situated in the southwestern part of Galileo Regio, a huge almost circular dark region in Ganymede's northern hemisphere. Although almost level today, it is a relic of a massive impact and once was a deep impact crater whose walls have slumped and its floor has risen isostatically, smoothing out the remaining topography with slush. The morphology of the larger palimpsests like Memphis Facula suggests that Ganymede's icy crust at the time of impact was about 10 km thick and was penetrated by the impact, allowing the slush and fluid beneath to fill and level out the crater. See also *Ganymede City ''3001: The Final Odyssey'' is a 1997 science fiction novel by British writer Arthur C. Clarke. It is the fourth and final book in Clarke's ''Space Odyssey'' series. Plot summary The novel begins with a brief prologue describing th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voyager 2
''Voyager 2'' is a space probe launched by NASA on August 20, 1977, to study the outer planets and interstellar space beyond the Sun's heliosphere. As a part of the Voyager program, it was launched 16 days before its twin, ''Voyager 1'', on a trajectory that took longer to reach gas giants Jupiter and Saturn but enabled further encounters with ice giants Uranus and Neptune. ''Voyager 2'' remains the only spacecraft to have visited either of the ice giant planets. ''Voyager 2'' was the fourth of five spacecraft to achieve Solar escape velocity, which allowed it to leave the Solar System. ''Voyager 2'' successfully fulfilled its primary mission of visiting the Jovian system in 1979, the Saturnian system in 1981, Uranian system in 1986, and the Neptunian system in 1989. The spacecraft is now in its extended mission of studying interstellar space. It has been operating for as of ; , it has reached a distance of from Earth. The probe entered interstellar space on November 5, 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganymede (moon)
Ganymede, a satellite of Jupiter (Jupiter III), is the largest and most massive of the Solar System's moons. The ninth-largest object (including the Sun) of the Solar System, it is the largest without a substantial atmosphere (albeit not the most massive one, which is Mercury). It has a diameter of , making it 26 percent larger than the planet Mercury by volume, although it is only 45 percent as massive. Possessing a metallic core, it has the lowest moment of inertia factor of any solid body in the Solar System and is the only moon known to have a magnetic field. Outward from Jupiter, it is the seventh satellite and the third of the Galilean moons, the first group of objects discovered orbiting another planet. Ganymede orbits Jupiter in roughly seven days and is in a 1:2:4 orbital resonance with the moons Europa and Io, respectively. Ganymede is composed of approximately equal amounts of silicate rock and water. It is a fully differentiated body with an iron-rich, liq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memphis, Egypt
, alternate_name = , image = , alt = , caption = Ruins of the pillared hall of Ramesses IIat Mit Rahina , map_type = Egypt#Africa , map_alt = , map_size = , relief = , coordinates = , location = Mit Rahina, Giza Governorate, Egypt , region = Lower Egypt , type = Settlement , part_of = , length = , width = , area = , height = , builder = Unknown, was already in existence during Iry-Hor's reignP. Tallet, D. Laisnay: ''Iry-Hor et Narmer au Sud-Sinaï (Ouadi 'Ameyra), un complément à la chronologie des expéditios minière égyptiene'', in: BIFAO 112 (2012), 381–395available online/ref> , material = , built = Earlier than 31st century BC , abandoned = 7th century AD , epochs = Early Dynastic Period to Early Middle Ages , cultures = , dependency_of = , occupants = , event ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palimpsest (planetary Astronomy)
A palimpsest , in planetary astronomy, is an ancient crater that has been degraded over time. They may also be referred to as "ghost craters", "degraded craters", "buried craters", or "pathological craters". Palimpsests have been identified on Mercury, the Earth, the Moon, Mars, Ganymede, Callisto, and possibly even Titan. On Mars, these features are morphologically described as craters that are "flat-floored, rimless, extremely shallow, without central peaks, and would probably represent what remains after erosion." On an icy moon of the outer Solar System, a palimpsest is a crater whose relief has disappeared due to creep of the icy surface ("viscous relaxation") or subsequent cryovolcanic outpourings, leaving a circular albedo feature, perhaps with a "ghost" of a rim. Icy surfaces of natural satellites like Callisto Callisto most commonly refers to: *Callisto (mythology), a nymph *Callisto (moon), a moon of Jupiter Callisto may also refer to: Art and entertainment *''Call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moons Of Jupiter
There are 82 known moons of Jupiter, not counting a number of moonlets likely shed from the inner moons. All together, they form a satellite system which is called the Jovian system. The most massive of the moons are the four Galilean moons: Io, Europa, Ganymede, and Callisto, which were independently discovered in 1610 by Galileo Galilei and Simon Marius and were the first objects found to orbit a body that was neither Earth nor the Sun. Much more recently, beginning in 1892, dozens of far smaller Jovian moons have been detected and have received the names of lovers (or other sexual partners) or daughters of the Roman god Jupiter or his Greek equivalent Zeus. The Galilean moons are by far the largest and most massive objects to orbit Jupiter, with the remaining 78 known moons and the rings together composing just 0.003% of the total orbiting mass. Of Jupiter's moons, eight are regular satellites with prograde and nearly circular orbits that are not greatly inclined wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galileo Regio
Galileo Regio is a large, dark surface feature on Jupiter's moon Ganymede. It is a region of ancient dark material that has been broken apart by tectonism and is now surrounded by younger, brighter material (such as that of Uruk Sulcus) that has been upwelling from Ganymede's interior. It is thought to be some 4 billion years old and is heavily cratered and palimpsested, but also has a unique distribution of furrows and smooth terrain that has been the subject of conflicting speculation regarding cause or origin. The distribution of smooth terrain on Galileo Regio suggests that the ancient crust of Ganymede was relatively thin in the equatorial region and thickened poleward in this area. The age relationships, morphology, and geometry of the furrow systems do not favor an origin by impact or tidal stressing. A possible, but speculative, origin is crustal uplift caused by a plume-like convection cell in a fluid mantle underlying a thin crust. Stratigraphic and morphologic relati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Lunar impact craters range from microscopic craters on lunar rocks returned by the Apollo Program and small, simple, bowl-shaped depressions in the lunar regolith to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth. Impact craters are the dominant geographic features on many solid Solar System objects including the Moon, Mercury, Callisto, Ganymede and most small moons and asteroids. On other planets and moons that experience more active surface geological processes, such as Earth, Venus, Europa, Io and Titan, visible impact craters are less common because they become eroded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isostasy
Isostasy (Greek ''ísos'' "equal", ''stásis'' "standstill") or isostatic equilibrium is the state of gravitational equilibrium between Earth's crust (or lithosphere) and mantle such that the crust "floats" at an elevation that depends on its thickness and density. This concept is invoked to explain how different topographic heights can exist at Earth's surface. Although originally defined in terms of continental crust and mantle, it has subsequently been interpreted in terms of lithosphere and asthenosphere, particularly with respect to oceanic island volcanoes, such as the Hawaiian Islands. Although Earth is a dynamic system that responds to loads in many different ways, isostasy describes the important limiting case in which crust and mantle are in static equilibrium. Certain areas (such as the Himalayas and other convergent margins) are not in isostatic equilibrium and are not well described by isostatic models. The general term 'isostasy' was coined in 1882 by the Ameri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topography
Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary science and is concerned with local detail in general, including not only relief, but also natural, artificial, and cultural features such as roads, land boundaries, and buildings. In the United States, topography often means specifically ''relief'', even though the USGS topographic maps record not just elevation contours, but also roads, populated places, structures, land boundaries, and so on. Topography in a narrow sense involves the recording of relief or terrain, the three-dimensional quality of the surface, and the identification of specific landforms; this is also known as geomorphometry. In modern usage, this involves generation of elevation data in digital form (DEM). It is often considered to include the graphic representation of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crust (geology)
In geology, the crust is the outermost solid shell of a rocky planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase (solid crust vs. liquid mantle). The crusts of Earth, Mercury, Venus, Mars, Io, the Moon and other planetary bodies formed via igneous processes and were later modified by erosion, impact cratering, volcanism, and sedimentation. Most terrestrial planets have fairly uniform crusts. Earth, however, has two distinct types: continental crust and oceanic crust. These two types have different chemical compositions and physical properties and were formed by different geological processes. Types of crust Planetary geologists divide crust into three categories based on how and when it formed. Primary crust / primordial crust This is a planet's "original" crust. It forms from solidification of a magma ocean. Towa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganymede City
''3001: The Final Odyssey'' is a 1997 science fiction novel by British writer Arthur C. Clarke. It is the fourth and final book in Clarke's ''Space Odyssey'' series. Plot summary The novel begins with a brief prologue describing the bioforms – dubbed the First-Born – who created the black monoliths. They evolved from "primordial soup", and over the course of millions of years, became a space-faring species. Perceiving that nothing was more precious than "mind", they catalysed the evolution of intelligent species wherever they went, by increasing the intelligent species' chance of survival. After visiting Earth, the First-Born found a way to impress themselves into the fabric of space and time, becoming effectively immortal. Meanwhile, the monoliths—implied to have been forgotten by their creators when they ascended to a higher state of being—continued to watch over their subjects. ''3001'' follows the adventures of Frank Poole, the astronaut killed by the HAL 900 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
