1·As comets go, it is a whopper.
在彗星里，它可算是个庞然大物。
—— 《柯林斯英汉双解大词典》
2·Comets are similar in composition to the gas giants.
彗星在组成上与气态巨行星相似。
3·Comets were formed around the same time the Earth was formed.
彗星与地球大约同时形成。
4·Loose collections of these ices and small rocky particles form into comets.
这些冰和小岩石粒的松散集合形成了彗星。
5·So to talk about where meteorites come from, we need to talk about comets and asteroids.
那么讲到流星体从何而来，我们就需要讨论下彗星和小行星。
6·Roids are, for the most part anyway, they are just smaller bits of asteroids and comets.
在很大程度上，Roids 只是小行星和彗星的小碎片。
7·I'm not going to go into any depth on comets and asteroids now, but we'll come back later and do that.
我现在不打算深入讨论彗星和小行星了，但是我们稍后会再回到这个点上，讨论这方面的内容。
8·Second, Jupiter's enormous mass prevents most Sun-bound comets from penetrating the inner solar system.
其次，木星的巨大质量阻止了大多数与太阳结合的彗星穿透太阳系内部。
9·We think meteors that crashed into the moon or tails of passing comets may have introduced water molecules.
我们认为，撞击月球的流星或经过的彗星尾巴可能会留下一些水分子。
10·The solar system also has two analogous classes of objects, smaller than planets—namely, asteroids and comets.
太阳系也有两类类似的物体，比行星还小——即小行星和彗星。