单词 | diurnal libration |
释义 | diurnal librationdiurnal librationDaily geometrical libration brought about by the change in the position of the observer with respect to the Earth–Moon line as the Earth rotates on its axis. This libration is most significant near the equator, where it amounts to 57′2″.6; this is equal to the Moon's mean equatorial horizontal parallax (see diurnal parallax). An observer closer to the poles will however experience an equivalent geometrical libration because of the displacement from the ecliptic. See also augmentation; physical libration. |
随便看 |
|
英语词典包含2567994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。