Orbital Simulations of Satellite Escape/Capture and the Origin of Satellites such as Triton
Abstract
We investigate satellite escape/capture in the context of the restricted, circular three body problem as applied to the Sun, Neptune, and Triton. We have computed a large number of coplanar prograde and retrograde orbital simulations over a range of initial distances and velocities. The satellite starts at superior conjunction within approximately 2 Hill radii of Neptune and has a velocity orthogonal to the Sunplanet line. Orbits with these initial conditions can be reflected with respect to time, so an escape is simply the reverse of a capture. We numerically integrate the equations of motion to compute the satellite's position until it escapes, collides with Neptune, or after 100 planetary years fails to escape, when computations cease. The initial distance x and velocity v in the restricted problem uniquely define the Jacobi constant C, a conserved energylike quantity. Plots of the simulation outcomes in the prograde and retrograde C, x phase spaces reveal distinct zones in which temporary satellites approach the planet closely enough that permanent capture can be effected by gas drag with a protoplanetary nebula or by collision with a preexisting satellite. Single and double closeflybys constitute the most common possible capture orbits. Long term multiple flyby orbits occur near the stability limits between bound and unbound orbits, and are more common among retrograde captures.
 Publication:

Lunar and Planetary Science Conference
 Pub Date:
 March 1993
 Bibcode:
 1993LPI....24...89B
 Keywords:

 Capture Effect;
 Celestial Mechanics;
 Gravitational Effects;
 Natural Satellites;
 Neptune (Planet);
 Orbital Mechanics;
 Satellite Orbits;
 Sun;
 Three Body Problem;
 Triton;
 Equations Of Motion;
 Simulation;
 Astrophysics