In this recipe, we will create a realistic Earth as shown in the following screenshot, using both image textures from the Web and some procedurals:
The image textures provided with this Cookbook have generally been heavily down-scaled and are good for demonstration purposes only (in this case, for a very distant Earth render). For better results with this recipe, replace these low-resolution images with high-resolution versions that you can find at these addresses:
Before you download anything, always take a look at the license of the images provided by any site you can find to ensure that they are released as freely usable, especially if you are going to use them for commercial work...