In space there is potential energy that is gravitational, similar in some ways to the potential energy associated with height on earth, but also different.
Two objects must be present and the potential energy increases with less distance between them, instead of more height like on earth.
The potential energy will be at a maximum absolute value when the radius between is smallest, but it is considered negative since the objects are moving toward each other.
They will also have the most kinetic energy right before they collide rather than zero kinetic energy when an object on earth hits the ground.