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Vesta is quite far away.
灶神星距地球的距离很远。
Like many asteroids, it has an orbit out between the orbits of Mars and Jupiter.
像其它许多小行星一样，它在火星与木星之间有自己的运行轨道。
Astronomers first spotted it when looking for a new planet they thought should exist between these two.
天文学家们首次发现它时是在寻找介于这两大行星间的另一个行星。
As I said, Vesta is quite small–about three hundred and twenty-five miles across.
正如我所说，灶神星是很小的—它的直径也就只有325英里而已。
So if it’s small and far away, how come we can see it from here?
那问题就是，它又小，距离我们又远，我们怎么能从地球上靠肉眼就看到它呢？
Vesta’s surface has a coating of pyroxine and olivine, two minerals that are actually also spewed up by volcanoes here on earth.
在灶神星的表面覆盖了厚厚的一层玄武岩和橄榄石，这两种矿物质都是由此处的火上喷发而出的。
They give it a whitish exterior that reflects well, making it just possible to see Vesta with your eyes, even when the only two larger asteroids, Ceres and Pallas, are completely invisible.
这两种矿物质使得灶神星的表面呈白色，且发光的效果相当好。如此一来，我们便仅凭肉眼就可以看到灶神星了。甚至在比它还大的另外两个小行星——谷神星和智神星都无法看到的情况下，我们还是能看到它。
