Part I of this series covered a simple Linux planetarium program, KStars.

But there are some questions KStars isn't very good at answering, like the question that began Part I: "What the heck are those really bright 'stars' in the sunset sky?" For viewing closeups of planets, monitoring the motion of the planets, getting precise predictions of events like eclipses, and other such information, you'll do better with a more powerful tool: XEphem.

XEphem is the oldest and arguably the best-known of the Linux planetarium programs. It's not included in most Linux distributions due to its license terms, but its source is available to download and the program is free for personal, educational or research use. You can buy it, too: $69.95 gets you a pre-compiled version of the program plus three CDs worth of extra data files that aren't in the free version. It's worth it if you're a sky junkie like I am.

You'll find XEphem at http://clearskyinstitute.com/xephem. Extract it and cd:

tar xzvf ~/Tarballs/xephem-3.7.3.tar.gz
cd xephem-3.7.3

XEphem builds a bit differently from the usual configure, make, make install sequence. See the file named INSTALL for instructions. You'll need Motif installed, like the libmotif3 package on Ubuntu. You'll probably also need some X development headers: if you get compile errors, try adding the packages xorg-dev and x11proto-print-dev, or your distribution's equivalent.

Once it's compiled, the INSTALL file also has instructions on how to install it on your system, depending on whether you want to install it as root for anyone who might use your system, or just for yourself.

Next: Navigating the Skies »