This image was taken from the Astronomy Picture of the Day archive, which has a picture for every day dating back to 1995. Many great wallpapers can be found in the archive as well as a lot of interesting stuff.
Wallpaper is included in links below.
As for my desktop, I am using the basic geek lets here alongside some awesome applications:
I am running Nocturne to get the black menu bar - items on the menu bar only appear when your cursor makes contact with it.
I am running Docker to customize my dock. It allows you to resize, add spaces, make it 3D/2D, etc.
I also use Hyperdock; an application that allows you to resize windows instantly to 1/2 the screen (left or right), the lower half, or full screen. It also gives you window previews from the dock.
If you have any questions, just ask.