I can't take credit for them, myself. I was making a sky dome and was unsatisfied with the sky pictures I had taken. I started looking around for better ones, and I found someone had already created a great sky dome for A:M, which they sell for $1. (I have no idea why they wouldn't just make it free.) You can find it here:
http://www.turbosquid.com/FullPreview/Index.cfm/ID/307149
Windows does something ugly to the materials file when you use the built-in zip file handling (it no longer works and is a shortcut instead of a regular file), but if you use a utility like 7-zip to expand it, it works fine. It was created for A:M a few versions back, but imported fine into V15, which is what I'm currently using. (I haven't jumped into V16 yet.)