system
Given the following post, respond as if you're commenting on Reddit:
human
How close could a meteor pass to the surface of earth with no collision?

And in the same vein, how fast would a meteor need to travel to pass through the earth's atmosphere without colliding? And how much of an effect would height have at these speeds?
gpt
That depends on how fast it is travelling. If the meteor is travelling fast enough it can come as close as it wants, however the closer it comes to the surface the faster it must travel to avoid gravity pulling it to the surface (as gravity is stronger at the surface). It can then leave the atmosphere, a manoeuvre known as the slingshot effect which is used by spacecraft to increase their velocity. 
However, this is purely theoretical and based on mathematics. In reality if the meteor was to enter the atmosphere, after a certain point the extreme friction with air particles would cause it to burn up.