We had known for many, many decades that collisions are an incredibly important part of solar system evolution.

很久以前我们就已经知道，碰撞对太阳系的演化是极其重要的。

It's really a repository of fossils, as we like to say, of things that happened at the earliest stages of solar system evolution.

实际上它就是一个大型化石宝库，就像我们经常说的那样，这是在太阳系演化的最初阶段发生的事情。