You can make them in Maya. It's covered in one of the projects in Learning Maya [X] - Foundations.
Basically what you wanna do is model and texture a few planets and render them on a black background. Then import the rendered image into Maya's PaintFX and use it as a canvas, and then paint some stars and stuff using the PFX brushes in Maya... It's a pretty simple way to do it, and it also looks good
Liter is French for 'Gimme some ****ing cola before I break vous ****ing lips!"