In addition to the large Main and Kuiper Belts, several special groups of asteroids have been identified.

The so-called Trojan asteroids are hiding—like soldiers inside the ancient Trojan Horse—in two regions along Jupiter's orbit where the gravitational forces of the sun and Jupiter balance each other. These points—60 degrees ahead and 60 degrees behind Jupiter—are called Lagrange points (after the mathematician who postulated them).

There are actually five Lagrange points in any two-body system. And so it may be that a much smaller collection of asteroid material has become snared along the orbit of our own planet at the Earth-moon Trojan points. All those wishing to build space colonies near Earth, please take note.