There, they have crashed repeatedly into one another to form fragments of various sizes.
在那里,它们之间的反复碰撞形成了各种尺寸的碎片。
Small asteroids are often little more than piles of dust and chondrules, the spherical pebblesof rock that formed from dust which melted in the heat of the young sun.
体积较小的小行星只不过是一些尘埃和陨石球粒的堆积物,其中这些圆状岩石形成于太阳早期高热量下融熔的尘埃。
Larger bodies such as Vesta, though, are more interesting.
但是象灶神星这样的较大天体更能引起人们的兴趣。
Vesta s size and density make it massive enough for its gravity to keep it roughlyspherical, like a proper planet.
与真正行星相仿,灶神星的尺寸和密度使其具备足够的引力保持基本的球体形状。
Another thing that makes Vesta planetlike is that it is split into distinct layers.
灶神星与行星的另一个相似点是它也分裂成不同的层。
The evidence suggests it has a nickel-iron core like the Earth s, overlain by a rocky mantle.
有证据表明它的地核也象地球一样由镍、铁元素组成,表面由岩石地幔覆盖。
Part of that evidence comes from its density and part from hundreds of chunks of rock, inthe form of meteorites,
【2015考研英语阅读小行星探测】相关文章:
最新
2016-10-18
2016-10-11
2016-10-11
2016-10-08
2016-09-30
2016-09-30