I know this has already been proposed but what about this:
- Roll 1D6 to determine if you have emty space (1-4) or something (5-6). If the latter, continue.
- Roll 1D6 to determine the overall terrain: 1: Black hole (centered on the map); roll 1D6-1 (min 1), this is the size. 2: Dust cloud. 3-4: Planetary zone: On the center, roll 1D6-1 (min 1) for size. Place as many moons (size 1) as the size -1 (hence, a very big planet (... Jupiter?) will have 4 moons. Of course, you could roll 1D6 per size -1 (Jupiter will roll 4 D6; on 4+, there is a moon. 5-6: Asteroid zone: Divide the map in six sectors. For each, roll 1D6: 1-3 place one or two large asteroid anywhere; 4-6 place an asteroid field (roll size as per planet)

I know, this may generate a lot of dice rolls, but after all, this is the game!

Marc