This weekend I spent a lot of time playing with some astronomy software.
I didn’t get to see any real-life stars due to cloudy nights, but on my
computer screen I saw them all, and even visited a few.
First, I played with
Celestia. It’s free and runs on
Windows, MacOS, and Linux. The best way to think of this program is as a
virtual space ship. You start out in orbit around Earth, and from there
you can fly anywhere you want to. Because navigating a true 3D space is
hard, there are handy short-cuts to just go and visit any object whose
name you know. You can accelerate or reverse time so you can go see what
a solar eclipse looks like from Sol’s point of view. Several space ships
and satellites are included as well, so it’s fun to check up on where
Cassini is right now. It’s just far enough past Saturn that the planet
is still large, but Titan is just a speck. And that’s the main thing you
learn from zooming around in space. Everything is really, really far
apart. Travelling from Earth to Alpha Centauri, you see our solar system
fade away almost instantly. Then nothing appears to change for a while,
until suddenly you’re there. There are also a ton of add-ons available
for Celestia, which contain anything from better textures for Mercury to
3D models of the Enterprise. Many people have used Celestia’s scripting
ability to create entertaining guided tours pointing out all kinds of
interesting galactic features. My only complaint really is there’s no
one big package available that contains a whole slew of the add-ons.
Each one needs to be downloaded individually and then installed
manually.
The second program I
toyed with is Stellarium. Like Celestia it
is free and runs on all the major operating systems. It aims to show you
space the way it would look in your back yard. It immediately looks very
slick, in no small part because of its use of anti-aliasing. The only
configuration you really need is to select where on Earth you want your
viewpoint to be. Then just accelerated time until it’s night, so you can
actually see some stars (or turn off the Earth’s atmosphere). This
program is ideal to find out what’s worth looking at tonight, where a
certain nebula will be, or whether Venus is up tonight or not. I then
spent a bunch of time coding up a
patch
which greatly reduces Stellarium’s framerate (and thus CPU usage) when
possible. It runs quite comfortably at 2fps when nothing’s going on.
Some day maybe I’ll try turning it into a screen saver.
