Viewing the Night Sky with Linux, Part III: Stellarium and Celestia Take You There
Stellarium's Superior ImagesParts I and II of this series covered covered the "planetarium" programs KStars and XEphem. They can answer pretty much any question about what's where and when in the night sky. But they don't really give you the feeling of being there like a couple of newer entries on the Linux astronomy scene: Stellarium and Celestia.
Stellarium and Celestia use hardware graphics acceleration. That means that if you're on an older, slower machine or one with a dodgy graphics card, you probably won't have much luck. On my main desktop machine, I couldn't get far before the system locked up and I had to reboot, but that seems to be an Ubuntu 8.04 bug -- it didn't happen under Ubuntu 7.04 or Fedora 9. If your computer is up to it, these programs are well worth trying. For one thing, they're gorgeous!
Navigating around the sky is easy in Stellarium: just drag, like you
would in KStars or Google Maps. Zoom in and out with your mouse wheel
or with the Page Up/Down keys. If it's daytime but
you want to see the sky for tonight, a couple of clicks on the
>> button near the bottom right will make time pass faster.
Be ready to click on > to go back to "real time speed" when
you get to the time you want. There are key bindings for zooming,
changing the time and nearly everything else, which you'll find
in the extensive online documentation.