Earth-1024x512.jpg is a resized image from http://maps.jpl.nasa.gov/ (courtesy NASA/JPL-Caltech) Image can be freely distributed but should credit the NASA/JPL-Caltec. brick001.jpg and metal003.gif are from http://www.grsites.com/archive/textures/ a collection of free background images. Earth-512x256.jpg is a version of an image that seems to be all over the Internet. I don't know its original origin.