Capture in restricted four body problem
  A number of irregular moons of the Jovian planets have recently been discovered. Most adequate way of their origin is capture, but detailed mechanism is unknown. A few possibilities are discussed: collisions, gas drag, tidal destruction of a binary asteroid. In this paper the capture process in restricted four body problem (RFBP) is researched. The interaction with regular satellite can be studied by this way as well as binary asteroid destruction in Hill sphere of planet. The energetic criteria of ballistic capture are studied and some numerical experiments are developed. It is confirmed, that capture in four body problem is more probable on retrograde than on prograde orbit. In according with our results, encounter with regular satellites is more effective mechanism to create an irregular satellite population, than a binary asteroid flyby. 
Alexey Rosaev
astro-ph.EP physics.space-ph