I saw a lot of interest for the Galaxy script
there is also this cool set of Astronomy plugin
http://www.hennigbuam.de/georg/gimp.html and
http://registry.gimp.org/node/2352Note that the most interesting from a artistic point of view are at the and of the list:
Quote:
"Artificial stars
Creates an artificial star distribution.
The interface is splitted: On the right side, you can set up the options for the star distribution, on the right side how they will be drawn. To actually calculate a star distribution, you need to click on the button, as recalculation might take very long for many stars.
Changes on the left side only affect the preview.
The sample distribution buttons give you an idea, what you can do with this plug-in.
Artificial galaxies
Creates an artificial galaxy.
Quite difficult to implement, only elliptical galaxies by now.
a tip , you may create different objects or starfield on different layers
as example one with stars one with a galaxy and then merge in lighten only mode
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MORE...if you want add planets 2 planet scripts
http://registry.gimp.org/node/8172http://registry.gimp.org/node/21Gas Giant
http://registry.gimp.org/node/10177if you want load space image from NASA at highest quality
http://registry.gimp.org/node/1627PS
Flaming Pear has some cool PS plugin for create artificial Moon, Sun etc
All commercial but free to try