@nosat @furgar if only there was a force pulling everything towards the center of the Earth (and any other large mass). In that situation, you'd expect the atmosphere to be in a gradient as the molecules would be pushing away from each other but also pulled to earth. Almost like a balance... Oh wait. And before you do the moon lander not being thick enough to hold a pressurized compartment, a soda can can hold 2 atmospheres and Apollo was only like 2/3 of an atmosphere