The moon and earths atmosphere

[willstaruss22]

I read somewhere that earths moon is a cause for earths relativly thin atmosphere, is that true. If so would that mean if the moon was smaller we would have a thicker atmosphere?

 

[Drakkith]

I've never heard that before. I can't really see it based on my own knowledge, but I'm not an astrophysicist or anything. Do you know where you read it by chance?