彗星和小行星

多数恒星也许还拥有若干行星、流星、彗星和小行星。

Most stars probably have their quota of planets , meteorids , comets , and asteroids .

彗星和小行星都要比行星小很多。

Both comets and asteroids are ... typically are smaller than planets .

一直以来地球总会跟彗星和小行星发生碰撞，但重大撞击的情况非常少见。

A : The Earth has always been subject to impacts by comets and asteroids , although big hits are very rare .

冰和有机物质，类似于柏油和煤炭，被认为是百万年前由彗星和小行星与水星碰撞时产生的。

Both ice and organic materials , which are similar to tar or coal , were believed to have been delivered millions of years ago by comets and asteroids crashing into the planet .

对于专业天文学家而言，那些恒星、彗星和小行星实在是太多了，无法对它们一一进行密切察看，因此，对于冥王星是1930年由业余爱好者克莱德·汤博发现这件事。

There are too many stars , comets and asteroids for only professional astronomers to keep an eye on , so we shouldn 't be surprised that Pluto was spotted by an amateur , Clyde Tombaugh , in1930 .

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，基本上说，这些流星体是由46亿年前太阳系诞生以来留下的废墟组成的。

So to talk about where meteoroids come from , we need to talk about comets and asteroids , which basically ... they 're basically made up of debris left over from the origin of the solar system 4.6 billion years ago .