radial velocity

例句：

1. 1. The spacecraft's radial velocity is increasing.
   宇宙飞船的径向速度正在增加。
2. 2.The radial velocity of the planet is changing due to its rotation.
   由于行星的自转，该星球的径向速度正在变化。
3. 3.Radial velocity measurements are crucial for understanding the motion of stars and planets.
   径向速度测量对于理解恒星和行星的运动至关重要。