The Asteroid Belt

Astronomers have noted and cataloged more than 6,000 asteroids with regular orbits, most of them concentrated in the asteroid belt, between the orbits of Mars and Jupiter. So far, every asteroid that has been noted orbits in the same direction as the earth and other planets—except one, whose orbit is retrograde (backward, or contrary to the direction of the planets). Although the asteroids move in the same direction—and pretty much on the same plane—as the planets, the shape of their orbits is different. Many asteroid orbits are more eccentric (the ellipse is more exaggerated and oblong) than those of the planets.
In early 2001, an asteroid-exploring probe orbited and finally landed on the surface of Eros. As it (slowly) crashed to the asteroid’s surface, it sent back tantalizing close-up images of the surface.