Fiddling with render layers and nodes, suddenly rendering only black

I’m working on an Earth render and was adding simple a glow effect with the compositor. I did a render and got nothing. Pure black. I disabled all nodes and selected only the render layer with Earth in it. Still black. I remember running into this problem before. I’ve attached the blend and would be grateful for help. I bet it’s something simple I’ve missed.

The node material on your planet isn’t set up properly, or you added it accidentally.

Indeed that was the case. The two spheres larger than the planet itself (Clouds and atmosphere.) accidentally had material nodes on, which caused the planet to render as pure black. Thanks for help.