Object Movement Phase

When do non-player controlled objects (such as asteroids, derelict
spaceships, etc.) move? In 2nd Edition it was after orders are written, but
before ship movement with a provision that fighters may dodge.

I would suggest making it just before ship movement (Phase 4.5). If a ship is
hit by the object, there is potential for damage (based on how massive the
object was and how fast it was traveling). If a ship's course passes through
the object, there is potential for damage. If the object would hit a fighter
group, the fighter group may use secondary movement to avoid the object,
otherwise there is potential for damage.

Comments, other suggestions?