I was watching the recent SE release and was particulary interested in the first portion of the movie... I always wondered why the Astronauts ruled out Earth as their current location. After all, that's where their navigation system was set to go (although they did have some system failures). Then I caught the line about there 'being no moon'. The astronauts knew that 2000 years had passed since leaving Earth. Seems odd that they never seriously considered the possibility that they were on Earth, but I guess that was the intended 'journey' for the movie. I haven't had a chance to watch the extras or the text commentary. Was it ever explained what happened to the moon?