Well, they do look cool, but you will need a lot more content before you can decide if it will be worth giving away as freeware. For something to be considered freeware I think it has to be a useful program, or decent game...
Those are really nice looking planets, but the planets are not the hardest part. The sun effects, atmosphere, gaseous clouds, asteroids, and rings are the more difficult aspects of the graphics in a space simulator.
You also must think...will someone find this program useful? What will it have that other similar programs do not?
Good Luck
Xander Moser - Bolt Software - Firewall