It wasn't till Huygens had two things: He had a good theory of planetary rings and how the solar system operated, and he had better telescopic, more fine-grain data in which he could figure out that as the Earth is going around faster -- according to Kepler's Laws -- than Saturn, then we catch up with it.
但是一直到惠更斯有了两样东西， 好的行星环理论和了解太阳系如何运转。 而且，当时他有更好的望远镜及更细微的数据， 从中他了解到当地球转得比土星更快速， 根据克卜勒三大定律，然后我们会追上它。