Astronomy software comes in many forms—from the details of computer intensive Grid computing of the distribution of stars (okay that’s astrophysics) to rendering the night sky in artistically detailed and sumptuous graphics. Being a devoted backseat observer to the evolution of the Universe in general and GNU/Linux software in specific, I thought it was time to show off what I consider to be the elite of desktop elegance. I will describe the installation and use of two astronomy related software packages: Stellarium and Celestia. These packages are visually appealing and fun to use. You never know, you might learn something along the way. And, if not, at least your eyes will feast upon some delicious candy.
- Figure 1: Stellarium with constellation art rendered
Stellarium (figure 1) is a sky renderer that marries accuracy and correctness with pure, unadulterated art. The software is a precision tool with hairline accuracies, which places you anywhere in the world at any time. You may even choose to view the heavens from the moon. Don’t be fooled by the software’s 0.8 version label (at the time of writing). This is one of the highest quality products in the market place.
Stellarium is one of the highest quality products in the market place
Celestia is a real time 3D space simulation; using open GL graphics (figure 2) and a plug in infrastructure, this software delivers an educationally valuable double punch. You may tour the solar system or with the help of extra datasets discover the scale of the known Universe. Both Stellarium and Celestia have a supportive community of developers and their project homepages reside on Sourceforge.
- Figure 2: Celestia’s view of Earth via the software’s default dataset
Memories
Why am I writing this? This is an article based on a remembrance of my father and reinforced by the brilliance of modern well-written open source Astronomy software. When I was five or six my father used to walk with me on cold winter nights from my house at the top of a country hill to the bottom where my sports club existed. Cold nights were perfect for viewing the stars. My father loved to tell me stories of the Greeks and the Romans and relate them to the patterns above. We had an understanding that during these quiet moments only the stars counted and nothing else was said. Therefore, it was with great pleasure that I recently rediscovered the software version of this experience. Living in a big city (Amsterdam), where city lights, air pollution and airplane and car traffic limit the quality of stargazing, a high quality software simulation is the nearest I can meaningfully get to the past.
Installation
There are many differences between a desktop environment and a minimalist production environment. At a guess, on my desktop there sit menu links to over a hundred useful or fun programs—from a rather overburdening array of addictively joyous games to utilities for burning CDs and reading RSS feeds. Regularly, there is a new set of updates. In fact, once in a blue moon, I sit at home with a glass of whisky and a dubious smile on my face installing the newest and the best. Package managers such as YUM (RPM) and APT (DEB) support this craving. Under this context, I would be foolish to compile and deploy new sources by hand. Updating all the software and seeking dependencies would not be achievable or pleasant. Therefore, for installing astronomy packages in a desktop environment, I would strongly recommend the use of a package manager. For a server environment, where you want a minimum of software tailored for specific tasks, the need is less stringent and perhaps even counter-productive.
For installing astronomy packages in a desktop environment, I would strongly recommend the use of a package manager
There are three main methods for installing software within a GNU/Linux environment. The primary method is the use of a package. Packages not only contain the software but are also structured to place the software correctly within the target GNU/Linux distribution. Complexities such as dependencies and file structures and placing menu options with the GNOME or KDE X windows environments are understood. Upgrading is trivial. Therefore, I will use this approach to install Stellarium and Celestia, even at the risk of stating the obvious. Zooming into the details of installation: there are two main competitors in the packaging domain RPM and Debian packages. For Debian, packages apt-get or tools sitting on top of apt-get do most of the heavy lifting. For RPM, YUM is currently my tool of choice. Both methods are best suited to a live internet connection, and if you are automatically updating your system every night through a cron job, then you will probably need a reasonably fast internet connection at that.
The second approach is to download the tar files and compile by hand. If you are lucky, things work out via a couple of standardized commands such as configure, make, make test, make install. If you are unlucky, patching and library dependencies can make for an evening of dependency hell.
The third and final approach is the use of an executable custom executable (normally called “installer”) that copies the right files in the right spot, and sits outside of DEB or RPM package control. However, I won’t be using this method in this article.
There are numerous GNU/Linux distributions, and the vast majority understand either RPM or DEB packaging; I will, therefore, describe both means of installation for Stellarium and Celestia. The target operating systems being both Fedora Core 5 for YUM/RPM and Ubuntu Breezy for APT.
