This splash screen is inspired by, and uses mostly the work of gnome-look user Internauta2000. I have only updated the background, the logo, and the script.

I have only tested this on a system with an NVidia display adapter running at 1920x1200.

The background image includes an image downloaded from the NASA picture of the day archive for 20101118. I believe that the NASA POTD images are in the public domain.

Since Internauta2000 created the vast majority of this splash, I recommend that you check out the original:
http://gnome-look.org/content/show.php/Ubuntu+10.04+and+10.10+Plymouth+Splash?content=128607