时差N小时 女灶神(下)（在线收听）

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。