Most people have no concept of how big this planet really is, and how insignificant humans are to this big rock. You could probably give every human on Earth 4 sq.ft. to stand on, and not even fill up Kansas. (Just my WAG)

The accepted border between our atmosphere and outer space is about 65 miles. Get the biggest globe you can find, measure off 65 miles on the surface, then come that distance up above the surface of the globe. That's a pretty damn thin atmosphere around this planet! We think those airliners are waaaay up there at 35-40,000 feet, but when you actually measure that distance from the surface of a globe, even a huge one, it's eye-opening.