Keplerian motion

例句：

1. 1.The Keplerian motion of the planets is a fascinating topic in astronomy.
   行星的开普勒运动是天文学中一个引人入胜的话题。
2. 2. The Keplerian motion of the planets was first described by the ancient Greek astronomer, Ptolemy.
   古代希腊天文学家托勒密首次描述了行星的开普勒运动。
3. 3. In the Keplerian motion model, the orbital period of each planet is directly related to itsmass and distance from the Sun.
   在开普勒运动模型中，每个行星的轨道周期直接与它的质量和离太阳的距离有关。