My Starry Background Disappeared While Compositing. Why? PLEASE HELP!

So while following along Blender Guru’s tutorial on making a realistic Earth, my starry background; which was appearing at first, disappeared after a few steps in the compositor. I will post my blender file as well as the BG image. Someone please help. This guy moves so fast in his tuts, is sometimes very vague, and I started trying to figure out how he did something and clicked a bunch of crap mid-stage and BOOM. BG GONE.

Here are the files: https://files.fm/u/czqzm5g3

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