How far does the atmosphere of earth reach into outer space?
It depends on your definition of atmosphere. If you refer to an altitde where you could comfortably breath without assistance then 3 miles, If you refer to the absolute height where there are no more molecular interactions caused by molecules created by the actions of the Earth then you are looking at 25 miles, maybe more. Orbiting satelliets and the ISS have to take atmospheric interactions into account when they correct altitudinal direction and movement. You may want to check out the science of temperature and its relation to atmosphere, look especially at the troposphere where temperaturs can be in the thousands of degrees but because of the lack of interaction between molecules it they have no chance to expend that energy. Consider also the reentry of the space shuttle and ask why they need a MAJOR amount of shielding, it is not because of the temperature of the air but rather the number of molecules impacting on the hull.
