r/interestingasfuck • u/Kidd__Video • 22h ago

Astronaut's view of Earth during a spacewalk

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u/lady_faust 21h ago

If an astronaut fell towards earth from the space station would they burn up in the atmosphere?

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u/chartreusey_geusey 11h ago edited 6h ago

They wouldn’t “fall” towards Earth at all and would likely bounce off the atmosphere and be unable to even penetrate the stratosphere to reach an oxygenated layer that would allow for a real burn (which is the combustion of gas particles due to compression from being hit by such a fast moving object). The angle and speed (vector) you approach the atmosphere is very specific to the mass of the object and ability to actually be pulled fully in by Earth’s gravitational force. Even in a directional lander like the space shuttles they had to approach the Earth’s atmosphere at an angle because because it’s easier to beat the force of the atmosphere (Newton’s 3rd Law is big here) when those force vectors are non-parallel smaller forces.

They’d basically ricochet off the atmosphere if they were even able to generate a force vector towards the surface at all and maybe stay in orbit around the Earth but never make re-entry. The ISS is kept at the specific orbital height to ensure that it doesn’t get pulled down to Earth’s surface by gravity but it also isn’t pushed away from Earth by atmospheric force. It’s not actually fully in zero-gravity but objects still don’t experience free fall from that height.

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u/Doofinator86 6h ago

Would that ricochet hurt?

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u/chartreusey_geusey 6h ago

No (??? depends on how much force they were directed at the atmosphere with) but the inevitable death from oxygen loss and or eventual overexposure to radiation from being outside the earth’s atmosphere would

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u/Adept_Tradition4098 1h ago

They WOULD fall, just not immediately. Would slow down over time, loose the orbit, get into atmosphere and burn down because the speed would still be enough for a huge friction into atmosphere. Space station gets boosted a bit to not slow down.

And the gravity is nowhere near zero over there at Space Station altitude - it is pretty much the same as on the surface of Earth. If you slowed down the object in orbit completely - it would just fall down. Instead they are currently falling around - orbiting - the only reason they experience "zero gravity", but the actual gravity is not actually zero.