| 单词 | shepherd satellite |
| 释义 | shepherd satellitenouna small moon orbiting near a planetary ring, whose gravitational pull helps confine the ring and the ring's extent. Also called shepherd moon . Words nearby shepherd satelliteShepard, shepherd, shepherd dog, shepherdess, Shepherd King, shepherd satellite, shepherd's check, shepherd's needle, shepherd's pie, shepherd's-purse, shepherd's weatherglass Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020 Scientific definitions for shepherd satelliteshepherd satellite [ shĕp′ərd ] A moon that orbits near the edge of a planetary ring, stabilizing the ring's particles through gravitational pull and confining the ring to a sharply defined band. For example, the moons of Uranus known as Cordelia and Ophelia are shepherd satellites that constrain Uranus's rings to a narrow band. It is believed that the gravity of the fast-moving inner satellite Cordelia causes the particles of the inner ring to speed up and move to outer orbits, while at the same time the gravity of the slower, outer satellite Ophelia decelerates outer particles, pushing them inward. The result is a compressed, well-defined ring. Also called shepherd moon The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved. |
| 随便看 |
英语词典包含192737条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。