Art for space game

Here's a sample play board (one of a 2x2 grid) for my new unnamed space game that I'm submitting for TheGameCrafter.com's vehicle game design contest, due in about a week.  In the game, players control ships and trade resources from planet to planet while completing missions and building ship upgrades.

The game board background image is NASA's Astronomy Picture of the Day from June 30, 2011, seen here:
http://apod.nasa.gov/apod/ap110630.html
It is of Star Factory Messier 17, taken by the European Southern Observatory's VLT survey telescope's OmegaCam.

The planets are textures from http://www.mayang.com/textures/ that I altered, recolored, and mapped to spheres.

The green grid I created in Adobe Illustrator, with shadows added in GIMP.  The wormhole art is a GIMP plasma rendering with a bunch of effects.  The pirate icon is clip art from the Open Clip Art Library (http://openclipart.org).  The starlanes (blue paths) are a path trace in GIMP with some gradient filling and border effects.  The text and disks around the planets I made in PowerPoint 2007.