Satellite, asteroid, and earth

I now have the satellite, earth, and asteroid all rendering together! There are still a few glitches though, see the image below.

There are still several issues with this render. The .blend file is getting so complicated I'm going to start .blend file version 3 soon to try to simplify it. Here are the current problems I see with this render.
1. There is a outline around the asteroid.
2. The glow effect that looks good on the satellite up close doesn't scale down well. It looked O.K. when the satellite took up most of the screen, but now it just makes it look blurry.
3. I would like to have some sort of depth of field.

Anyway, I'm going to start working on blend file version 3, and see how that goes. It's really coming together nicely so far.