Asteroids in orbital intervals opposite planets. What are they like?

Question

I have heard that there are pockets of material following the earth in its orbit at 120 degrees and 240 degrees, and following Jupiter in its orbit at even intervals unaffected by resonant gravitational pulls of neighboring satillites. What is known of these areas of space? How much material is there? Wouldn't it be fairly economical to send an unmanned probe there?

Answer 1

Hi. I think you are looking for "Trojan orbits". All massive bodies have them and they are horseshoe shaped. http://en.wikipedia.org/wiki/Trojan_asteroid