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Crater Depth
The depth of an impact crater in a solid planet or moon may be measured from the local surface to the bottom of the crater, or from the rim Rim may refer to: *Rim (basketball), the hoop through which the ball must pass **Breakaway rim, a sprung basketball rim * Rim (coin), the raised edge which surrounds the coin design *Rim (crater), extending above the local surface *Rim (firearms), ... of the crater to the bottom. The diagram above shows the full (side) view of a typical crater. Depth "A" measures from the surface to the bottom of the crater. Depth "B" measures from the mean height of the rim to the bottom of the crater. Concepts and Measurement Using the following concepts, a crater is measured: *Measurement *Scales *Geometry *Graphing data *Drawing conclusionsCrater Depth , National Optical Astronomy Observatory, Re ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planet
A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a young protostar orbited by a protoplanetary disk. Planets grow in this disk by the gradual accumulation of material driven by gravity, a process called accretion. The Solar System has at least eight planets: the terrestrial planets Mercury, Venus, Earth and Mars, and the giant planets Jupiter, Saturn, Uranus and Neptune. These planets each rotate around an axis tilted with respect to its orbital pole. All of them possess an atmosphere, although that of Mercury is tenuous, and some share such features as ice caps, seasons, volcanism, hurricanes, tectonics, and even hydrology. Apart from Venus and Mars, the Solar System planets generate magnetic fields, and all except Venus and Mercury have natural satellites. The giant pla ... [...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 often colloquially referred to as ''moons'', a derivation from the Moon of Earth. In the Solar System, there are six planetary satellite systems containing 209 known natural satellites altogether. Seven objects commonly considered dwarf planets by astronomers are also known to have natural satellites: , Pluto, Haumea, , Makemake, , and Eris. , there are 442 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 Neptune� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rim (craters)
The rim or edge of an impact crater is the part that extends above the height of the local surface, usually in a circular or elliptical pattern. In a more specific sense, the rim may refer to the circular or elliptical edge that represents the uppermost tip of this raised portion. If there is no raised portion, the rim simply refers to the inside edge of the curve where the flat surface meets the curve of the crater bottom. Simple craters Smaller, simple craters retain rim geometries similar to the features of many craters found on the Moon and the planet Mercury. Complex craters Large craters are those with a diameter greater than 2.3 km, and are distinguished by central uplifts within the impact zone. These larger (also called “complex”) craters can form rims up to several hundred meters in height. A process to consider when determining the exact height of a crater rim is that melt may have been pushed over the crest of the initial rim from the initial impact, ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters
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 erode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
