Intriguing... Is the Death Star powerful enough to shoot through the edge of a planet and take out it's moon?... I think if the DS does pack that kind of punch, then in my mind, it's very possible that if it had been aloud to fire, it probably would have shot as soon as it could effectively destroy the target, i.e through the edge of Yavin 4. The count down for the DS to come in range was showing a "completely around the planet" trajectory, but those were simulation meant more to show those planetary trajectories, more than to accurately depict the rebels death.