As for the drifting of the wreckage, there's not exactly anything propelling them in any direction as far as we know at the moment. The lack of air in space means a lack of momentum unless some force is directly acting on an object.
air does the opposite of that; it supplies friction
mass has (or
is a measure of 'how much') inertia, which is basically the resistance to a change in state of motion. objects that are moving will continue to move at the same speed, in the same direction, until something accelerates them to stop, slow down, or change direction. objects that are still will require acceleration to begin moving.
force causes acceleration (in fact, acceleration and force are directly proportional), but velocity (and in turn, so long as mass is the same, momentum) stays constant unless acted on by an external force, e.g. friction caused by air
physics 101 by blockland.forum.us.co.uk.smf.
biz
[addendum: in actual fact there is air in space, just an insignificant amount in comparison to what you would find in an atmosphere]
btw i'm not tryin to be all internet big guy muscle flex i just rly like physics