Eli5: how does the earths atmosphere work? E. G how does the oxygen not fade away into the cosmos

Question

I’ve had a conversation with a guy that claimed “it’s a myth”. An obvious face-palm, I know, but I realized I’d like to know.

In: 71

Answer 1

We actually do lose alot every day to space. Especially our helium, as it is the lightest gas. Some oxygen escapes and is blown away by the solar wind as well. But luckily for life on this rock, the majority is held around us by good old fashioned gravity.