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.