Author's Note: I'm reasonably happy with the result, this is the best I could do with the amount of motivation I had on hand. Not 100% happy with the moon, personally I think it looks a bit cheezy.
I used the GIMP. Photoshop is for people who want to fund the corporate machine, or for wealthy people or pirates!.. Yarr!
I used alot of erase tool, alot of blending, a bit of blur, a bit of burn and used the perspective tool to shape the moon for it's new location. With the stars that I manually placed I ended up with about 7 layers before flattening.
Images used:
http://www.sxc.hu/photo/1221586
http://www.sxc.hu/photo/1221586
http://www.sxc.hu/photo/155318
http://randomnista.files.wordpress.com/2008/01/hubble_image011.jpg