2006-09-11 07:36:31 · 5 answers · asked by teton 4 in Cars & Transportation ➔ Aircraft
At about 85 km. up -- that's the boundary of the mesosphere, where "useful" atmosphere ends. Beyond that there is still atmosphere, but it's not dense enough to hold thermal energy in any significant way.
2006-09-11 07:40:37 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Well you need to define where the atmosphere ends and start .. Its difficult to say since there is no abrupt boundary, it's a continuous change from the sea level to the deep space.
After 50km the atmosphere is only 1/1000 of the sea level density. At 100km 1/4E9, at 150km 1/1E12.
It seems to be generally admitted that the atmosphere ends somewhere beyond 600km. After this comes the exosphere, which is a wide zone where the atmosphere merges with interplanetary gases. It does not mean that there is no more gas after this though, even intergalactic space has some atoms floating around.
2006-09-11 14:53:41 · answer #2 · answered by Anonymous · 1⤊ 0⤋
The International Space station orbits at an altitude of 350 or so kilometers above the earths surface... im not sure if that's where the actual atmosphere ends though
2006-09-12 22:20:17 · answer #3 · answered by mcdonaldcj 6 · 0⤊ 0⤋
The lowest altitude that a spacecraft can orbit the Earth without the upper atmosphere slowing it down enough to force a re-entry is about 80 miles. Anything below is is regarded as a Suborbital trajectory.
2006-09-11 15:27:20 · answer #4 · answered by Anonymous · 0⤊ 0⤋
350,000 ft is where the air is so think it can't be measured (as far as impact to a flight vehicle).
2006-09-11 22:28:58 · answer #5 · answered by Drewpie 5 · 0⤊ 0⤋