In this recipe, we will create a realistic planet Earth using image textures available on the Web:
The image textures provided with this book have generally been heavily down-scaled and are good only for demonstration purposes (or, in this case, for a very distant Earth render). For better results with this recipe, just replace these low resolution images with hi-res versions that you can download, for example, from these addresses:
Before you download anything, always have a look at the license of the images provided by any site you can find, to be sure they are released as freely usable, especially if you are going to use them for commercial works. The preceding links should be good enough, but on the Internet things can change...