请输入您要查询的字词:

 

单词 Triton
释义
Triton

Astronomy
  • The largest satellite of Neptune, 2707 km in diameter; also known as Neptune I. It lies 354 760 km from Neptune’s centre, and orbits in a retrograde direction every 5.877 days at an inclination of 156°.9 to Neptune’s equator. Its period of axial rotation is the same as its orbital period. Triton was discovered by W. Lassell in 1846, a few weeks after the discovery of Neptune itself. Triton has a tenuous nitrogen atmosphere with some methane. The surface pressure, however, is only about 16 μ‎bar, little more than 10−5 of the Earth’s atmospheric pressure, and its surface temperature is −235°C, the coldest surface so far measured in the Solar System. Triton has a young icy surface with an average albedo of 0.72, one of the brightest surfaces of any planetary satellite. Few impact craters are seen on Triton, but it has many different types of terrain including smooth plains, hummocky plains, cantaloupe terrain, long linear features, and also a large, probably seasonal, polar cap of nitrogen ice. The Voyager 2 space probe photographed dark plumes rising from dark spots on the surface to an altitude of 8 km before drifting downwind. These plumes may be geyser-like eruptions from subsurface pockets of liquid nitrogen or methane.


Space Exploration
  • The largest of Neptune's moons. It has a diameter of 2 700 km, and orbits Neptune every 5.88 days in a retrograde (east to west) direction at a distance of 354 000 km. It takes the same time to rotate about its own axis as it does to make one revolution of Neptune.

    It is slightly larger than the planet Pluto, which it is thought to resemble in composition and appearance. Probably, Triton was formerly a separate body like Pluto but was captured by Neptune. Triton was discovered in 1846 by English astronomer William Lassell (1799–1880) only weeks after the discovery of Neptune. Triton's surface, as revealed by the Voyager 2 space probe, has a temperature of 38 K (−235 °C), making it the coldest known place in the Solar System. It is covered with frozen nitrogen and methane, some of which evaporates to form a tenuous atmosphere with a pressure only 0.00001 that of the Earth at sea level. Triton has a pink south polar cap, probably coloured by the effects of solar radiation on methane ice. Dark streaks on Triton are thought to be formed by geysers of liquid nitrogen. The surface has few impact craters (the largest is the Mazomba, with a diameter of 27 km), indicating that many of the earlier craters have been erased by the erupting and freezing of water (cryovulcanism).


Geology and Earth Sciences
  • A satellite of Neptune, with a diameter of 2705.2 km; mass 214.7 × 1020 kg; mean density 2054 kg/m3; visual albedo 0.7. Its orbit is retrograde.


随便看

 

科学参考收录了60776条科技类词条,基本涵盖了常见科技类参考文献及英语词汇的翻译,是科学学习和研究的有利工具。

 

Copyright © 2000-2023 Sciref.net All Rights Reserved
京ICP备2021023879号 更新时间:2024/12/25 2:45:01