Tonight my transport had the misfortune of of hitting an asteroid... The next turn while trying to get away from the asteroid I collided with another ship thus stopping me from getting off the asteroid....

Question: do I get an addition damage roll from staying on the asteroid?

As stated on the main forum: Yes. You landed on an obstacle this turn, irrespective of whether you were on it the turn previous.
You are, however, allowed to slap that stupid grin off your opponent's face if it causes your ship to die.

Similarly, if your maneuver template lands on the asteroid as you move off, you'd roll damage and lose your action again.
If you collide with a ship and stay on the asteroid, you just lose your attack as well.

Rocks are bad, kids, m'kay?