时差N小时:女灶神(下)

Vesta is quite far away.

Like many asteroids, it has an orbit out between the orbits of Mars and Jupiter.

Astronomers first spotted it when looking for a new planet they thought should exist between these two.

As I said, Vesta is quite small–about three hundred and twenty-five miles across.

So if it’s small and far away, how come we can see it from here?

Vesta’s surface has a coating of pyroxine and olivine, two minerals that are actually also spewed up by volcanoes here on earth.

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.

使用搜索工具,可以更快找到你想要的资料!

特别推荐
最新资料