[Suicide Junkie]

Its gravitational potential energy. If the object falls down into any gravitational well, that turns back into kinertic energy.

What goes up does *not* have to come back down. That's the point of escape velocity.

You recall those distorted funnel grid paper things that are always used on tv to show gravity fields?
The height represents the potential energy. If the object moves into the depressions, its potential energy is decreasing. In a vaccuum, that pretty much all turns into kinetic energy and back when the object orbits around.