Lifehacker has an amazing space desktop theme available for Windows, MaC, and Linux. Check out their post here. It includes the above wallpaper plus customized skins and icons to make your desktop look like Spaaaaace! The following are included for Windows:

The Goodnight Tale wallpaper from DeviantArt
The Rainmeter system management and configuration utility for Windows
The Encoded skin for Rainmeter to get the date and weather
The Enigma suite for Rainmeter for the system stats on the right side of the screen
The Google bar for Rainmeter for the search bar in the upper right
StarDock's ObjectDock to replace the Windows taskbar
The Token icon set for the dock at the bottom

Check it out at Lifehacker!