Hello fabio, a challenge is better with more competitors so welcome to this month challenge!
Your idea is really interesting and we don't see enough space maps here. For suggestions about your map i guess it's a bit soon for constructive critics, if i had chosen a space map like this i think i would first focus on the the space field in the background for a nice render. I've tried a few photoshop tuts found with the keyword "space art" and some tips are really usefull to give nebulae or galaxy effects to a background.