The entire surface of the largest asteroid, Ceres, does not equal the republic of Mexico in area.

But Ceres itself is gigantic in comparison with the vast majority of the asteroids, many of which, it is believed, do not exceed twenty miles in diameter, while there may be hundreds or thousands of others still smaller--ten miles, five miles, or perhaps only a few rods, in diameter! Curiously enough, the asteroid which appears brightest, and which it would naturally be inferred is the largest, really stands third in the order of measured size.

This is Vesta, whose diameter, according to Barnard, is only 239 miles.

It is estimated that the surface of Vesta possesses about four times greater light-reflecting power than the surface of Ceres.

Some observations have also shown a variation in the intensity of the light from Vesta, a most interesting fact, which becomes still more significant when considered in connection with the great variability of another most extraordinary member of the asteroidal family, Eros, which is to be described presently.
The orbits of the asteroids are scattered over a zone about 200,000,000 miles broad.