Yea the moon is pretty large when looking at it from the tower, or the cosmodrome. The scales are a bit off, I mean, from earth, Mars is just a star, a little point of light, now obviously the moon isn't on the earth surface, but I doubt that you'd be able to see mars in detail with a sniper scope on the moon like you can in Destiny.

Guess I never paid attention to it. Now that I think about it though, doesn't Destiny take place in an unknown amount of time after the collapse? The moon should look farther away if anything. But who knows.... space magic and all that.