Earth's true shape?

True, from space we have learned that it is round, but is it? My theory is that from space only so much can be described. I think that it is the atmosphere that is round and that, even though the atmosphere is invisible to the naked eye, it works like a mirror and when the vast shadow of space combines with the lights and rays from the sun it creates a cicular form thus making it impossible to determine the true form of our planet from space. ~DsRath