Either of two points in an orbit, one being at maximum and the other at minimum distance from the controlling central body. The apogee and perigee of the Moon are apsides, as are the aphelion and perihelion of a planet.
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。