Satellite capture as a restricted 2 + 2 body problem

A restricted 2?+?2 body problem is proposed as a possible mechanism to explain the capture of small bodies by a planet. In particular, we consider two primaries revolving in a circular mutual orbit and two small bodies of equal mass, neither of which affects the motion of the primaries. If the small bodies are temporarily captured in the Hill sphere of the smaller primary, they may get close enough to each other to exchange energy in such a way that one of them becomes permanently captured. Numerical simulations show that capture is possible for both prograde and retrograde orbits.