Ever stare up into the sky and wonder what lies beyond the earth? Ever wished you could travel among the stars, studying planets and galaxies? Ever looked up and simply wondered how far away the moon is anyway? If you have any interest in astronomy, this week’s Freeware Frenzy is for you. I will be taking a look at the free space simulation software Celestia 1.4.1. While designed for science education, anyone can appreciate spending time with Celestia.

Installation is a snap, and in no time you are up and running. Celestia is a tad imposing at first, so I went into the Help section. Celestia’s included help only gives you a run down of all the keyboard shortcuts, and there are a bunch of them. You’ll want to go to the website and download the PDF manual.  It will run through the various features, controls and setup options for Celestia. With plenty of photos and links, you can quickly find help with whatever you need. A casual glance will be enough to get by, but it is worth the read to fully appreciate Celestia’s capabilities. Celestia even includes a Demo Mode that will run through some of the capabilities of Celestia.

The first thing worth noting is that Celestia is a resource hog. I turned off all other programs and booted Celestia to find that it used 45MB of ram and 100% of my CPU. Celestia’s developers recommend a Geforce 5xxx or Radeon 9xxx or higher for best results. The more power and memory your video card has, the easier you’ll zoom through high resolution textures. You can even check your FPS using the “~”. I averaged around 75fps with my X800XL and high res textures setting.

So now that I’m ready to go, let’s run through the feature list in Celestia. Navigation is paramount. Considering the vastness of space, you’ll want reach your destinations quickly. Luckily you can travel to various objects a few different ways.

The easiest way to go to most bodies, assuming you do not make any typos, is to simply press Enter, type in a planet, moon or other object. If Celestia has it available, another Enter will send you hurtling through space until you see that object. Tour Guide, under the Navigation menu, will also take you directly to some selected objects, and includes a small snippet of information on them. I would have appreciated more info and more objects with this feature, especially for educational purposes.

You will also find three main browsers under the Navigation menu. With the Eclipse Finder you simply choose solar or lunar, your planet of choice (though who is going to notice a lunar eclipse on Jupiter?), enter a date range and Celestia will compute all future eclipses. Keep an eye out for a solar eclipse in September 2006. The Star browser includes hundreds of stars which can be organized by Nearest, Brightest or With Planets. The Solar System Browser lets you choose a planet, moon or other object in the solar system and you can travel straight there. When you arrive at your destination, Celestia shows you some basic information for whatever heavenly object you are looking at, including viewing distance, radius, day length and temperature.

Celestia puts a strong emphasis on Time, letting you speed it up, slow it down and switch from real time to any date you wish. Custom times let you watch missions such as comets and meteor collisions as if you were there. Celestia allows you to Sync Orbit, so you can watch any object in movement. These movements are fully synchronized, so not only does the earth revolve around the sun, but you can zoom out and see the moon orbiting the earth. Celestia has a variety of View customizations including star filters, comet trails, night sky lighting, etc. You’ll need a powerful video card for all of the eye candy, but it does make for a richer space exploration experience. You can also split up the main window to view various objects at once.

Celestia not only allows you to capture images, but also to record movies. You can save them in a variety of resolutions and formats, so have an idea what kind of space requirements you have. An uncompressed DivX file at 320×240 that was 1minute long was only 900k. However, an uncompressed DivX file at 640×480 that was only 15 seconds came in at a whopping 204MB.

Celestia is also very expandable. Users can create and submit their own scripts and textures for anyone to download. From canyons on Mars to Star Wars starships, you can find anything. I was able to watch the Apollo 11 modules orbit the moon with a small add-on. The dedication to this program is very apparent in the community.

All in all Celestia is an excellent program for anyone with an eye on the sky. It may not be practical for those of us outside of the teaching world, but I couldn’t help but zoom around to different planets just for the fun of it. Grab the 14MB program here: http://www.shatters.net/celestia/