I couldn't find a high resolution earth land mask/matte online, so I hacked one together. You can have it for free! I'm using it for a 3d earth model in Blender. This tutorial below is great, but if you want to zoom in, you're going to need larger textures. This land matte was hard to find in high resolution. You can use it to mask out reflection on the land.
Download Land Mask: https://drive.google.com/file/d/0B2YvCi82WCwFWmt6dkJtV2VRM0E/view?usp=sharing
NASA has kindly provided all the other high-res textures you will need.