“Enceladus”的概念、定义、翻译、参考文献-科学参考

Enceladus

Astronomy

The fourteenth-closest satellite of Saturn, distance 238 042 km, orbital period 1.370 days; also known as Saturn II. Its axial rotation period is the same as its orbital period. Enceladus was discovered in 1789 by F. W. Herschel. It is 513 × 503 × 497 km in diameter. Impact craters cover part of its surface, but over half the surface consists of smooth plains with few craters. The smooth plains are separated from the cratered areas by long sinuous ridges. There are also grooves, folds, faults, and other signs of large-scale fracturing and past geological activity on the surface. Some form of cryovolcanic process is still underway—plumes of ice particles and water vapour were observed rising from its southern polar region by the Cassini spacecraft. Enceladus has an albedo of nearly 1.0, which means that it reflects nearly all the sunlight that falls on it. Hence it can absorb very little heat, and the surface temperature is −201°C. Enceladus lies within Saturn’s diffuse E Ring and contributes material to the ring.

Geology and Earth Sciences

A major satellite of Saturn, discovered in 1789 by Sir William Herschel. It has the brightest surface of any body in the solar system (albedo more than 0.9), composed of clean, fresh ice (not necessarily water ice). The surface is cratered, but there are also smooth plains and long linear cracks and ridges. The surface appears to be young, probably less than 100 Ma old, indicating it has been geologically active until very recently, and possibly is still active with some kind of water volcanism. This activity may make Enceladus the source of the material comprising the tenuous E ring of Saturn. Enceladus is much too small to be heated by radioactive decay; the heat would have dissipated long ago. The orbit of Enceladus is locked in a 1:2 resonance with Dione, which may provide some tidal heating, but probably not enough to melt water ice. Enceladus is 238 020 km from Saturn; its radius is 249.1 km; mass 0.73 × 10²⁰ kg; mean density 1120 kg/m³; visual albedo 1.0. The Cassini mission to Saturn includes a fly-by of Enceladus.

单词	Enceladus
释义	Enceladus Astronomy The fourteenth-closest satellite of Saturn, distance 238 042 km, orbital period 1.370 days; also known as Saturn II. Its axial rotation period is the same as its orbital period. Enceladus was discovered in 1789 by F. W. Herschel. It is 513 × 503 × 497 km in diameter. Impact craters cover part of its surface, but over half the surface consists of smooth plains with few craters. The smooth plains are separated from the cratered areas by long sinuous ridges. There are also grooves, folds, faults, and other signs of large-scale fracturing and past geological activity on the surface. Some form of cryovolcanic process is still underway—plumes of ice particles and water vapour were observed rising from its southern polar region by the Cassini spacecraft. Enceladus has an albedo of nearly 1.0, which means that it reflects nearly all the sunlight that falls on it. Hence it can absorb very little heat, and the surface temperature is −201°C. Enceladus lies within Saturn’s diffuse E Ring and contributes material to the ring. Geology and Earth Sciences A major satellite of Saturn, discovered in 1789 by Sir William Herschel. It has the brightest surface of any body in the solar system (albedo more than 0.9), composed of clean, fresh ice (not necessarily water ice). The surface is cratered, but there are also smooth plains and long linear cracks and ridges. The surface appears to be young, probably less than 100 Ma old, indicating it has been geologically active until very recently, and possibly is still active with some kind of water volcanism. This activity may make Enceladus the source of the material comprising the tenuous E ring of Saturn. Enceladus is much too small to be heated by radioactive decay; the heat would have dissipated long ago. The orbit of Enceladus is locked in a 1:2 resonance with Dione, which may provide some tidal heating, but probably not enough to melt water ice. Enceladus is 238 020 km from Saturn; its radius is 249.1 km; mass 0.73 × 10²⁰ kg; mean density 1120 kg/m³; visual albedo 1.0. The Cassini mission to Saturn includes a fly-by of Enceladus.
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