Some people think astronomy is a waste of time. Well, if you are reading this post and you have that opinion, get over it! Astronomy is a good interesting science!
Anyway, when I started looking into astronomy software, I found out that 99% of it was open source, and obviously Linux compatible.
So, I found two programs, Celestia and Stellarium. Celestia is a program like Google earth but for the whole universe and Stellarium is for viewing the stars at any time or place. At the time, I preferred Celestia. Now I prefer the well improved Stellarium which is in the screenshot on the top left of this post.
So, if you have any small interest in astronomy live in a place that is really cloudy, try out this!