1.A number of recent missions have ventured to comets.
最近的许多太空任务与彗星有关。
2.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。
3.Comets are similar in composition to the gas giants.
彗星在组成上与气态巨行星相似。
4.As comets go, it is a whopper.
在彗星里，它可算是个庞然大物。
5.Lulin, like all comets, isa clump of frozen gases mixed with dust.
鹿林彗星和其他彗星一样，是一堆冰气体和尘埃组成。
6.Because if comets battered the moon, they probably hit the Earth, too.
因为如果彗星能够把水带到月球，同样很可能带到地球。
7.Once in deep space, it went though the same process of aggregating into comets.
进入外太空后，彗星形成的过程就和以前所知并无二致了。
8.Any school kid can tell you that comets are made of ice.
随便找个小学生都会告诉你，彗星是由冰组成的。
9.About the same time, though, scientists realized comets might contain decaying radioactive isotopes that could have warmed cometary interiors to temperatures that caused the interiors to evolve.
