There's something deliciously dramatic about the moon's monthly disappearing act. One moment it's dominating our night sky, and the next — poof! — it's gone, only to make a grand re-entrance days ...

This week in Starwatch I want to go back to basics when it comes to the moon. So why does the moon change shape? Why is it a crescent on one night, a half-moon another night, and a full moon on yet ...