astronomical nutation

例句：

1. 1. The planet's orbital mechanics are responsible for the astronomical nutation of its moon.
   行星的轨道力学负责其月亮的天文摆动。
2. 2. Astronomers have been studying the effects of gravitational forces on the astronomical nutation of planetary bodies.
   天文学家一直在研究引力对行星体天文摆动的影响。
3. 3. The astronomical nutation of the planet's moon is a crucial factor in determining its elliptical orbit.
   行星的月亮的天文摆动是确定其椭圆轨道的关键因素。