Apollo and Amor

Apollo asteroids cross the orbit of Earth. Amor asteroids graze the orbit. Several are discovered each year, and there are an estimated 800 to 2400 of these types of asteroids with diameters of more than 1 kilometer. There are over 300,000 with diameters of more than 100 meters. Many of these asteroids are Carbonaceous Chondrites. The Amor asteroid 433 Eros is in such an orbit that the delta-vee required to retrieve materials from is is less than 4 kps. This is a lower transfer energy than is required to bring material up from the small gravity well of the moon.