  Up to symmetries, the orbits of three equal masses under an inverse cube
force with zero angular momentum and constant moment of inertia can be
reparametrized as the geodesics of a complete, negatively curved metric on a
pair of pants. The ends of the pants represent binary collisions. Here we will
examine the visibility properties of such negatively curved surfaces, allowing
a description of orbits beginning or ending in binary collisions of this 3-body
problem.
