I’ve been using astronomy pictures as my desktop background for years. In a never-ending search for the perfect background, however, I’m now using an Xplanet-generated image of the Earth and the Moon, with the Veil nebula behind them as additional eyecandy. Click on the sample image for a larger version — but I’ll tell you how to generate your own.
If you’re using KDE like I do, some good soul already set up all the pieces for you: open the “Advanced Background Settings” window, click on “Use the following program for drawing the background:” and select “xplanet” from the list. You’ll probably want to tweak the options and maybe even the Xplanet configuration file. This is the command line I’m using:
xplanet -config desktop -latitude 30 -longitude 11 -radius 35 -glare 0.001 -base_magnitude 0 -background ~/pics/noao/veil_1280x1024_darkened.jpg -geometry %xx%y -num_times 1 -output %f.jpg && mv %f.jpg %f
I’m setting the Sun glare to 0.001 because the Sun passes just above the top of the picture at night and the glare would turn the background into a pale yellow splotch.
I’m setting the base magnitude to 0 because the background picture already provides all the stars I want. I scaled the background image to the right size and darkened it a little bit to get rid of the nebula’s faint diffuse glow and to reduce the amount of stars.
Here’s the important part of the configuration file:
[default]
max_radius_for_label=0 # never draw labels[sun]
shade=100 # No night side![earth]
magnify=40[moon]
magnify=40
The bodies are enlarged 40 times, otherwise you wouldn’t see the Earth and Moon in the same image very often.
Of course you’ll want to add color maps, a specular map and a bump map. For the image above I used maps from James Hastings-Trew’s Planetary Pixel Emporium. Note that I’m not using a bump map on the Moon because it would add too much detail.