Help me understand here: aren't we talking about a volume of space with a radial cross section significantly larger than the surface of the earth?
I find it hard to believe we've launched so many things that collisions have become likely.
Any actual data out there on the number of objects in orbit and the likelihood of collision?
What am I missing?
https://www.quora.com/Which-one-makes-a-bullet-dangerous-its...
The speeds at which even the smallest debris hit other satellites are immense, compared to what we are used to in our surroundings. International Space Station moves at the speed of 17 thousand (!) miles per hour. Even the small pieces of something else moving at the different speed or direction will be extremely destructive, see again the explanation about how the bullets "work."
Then consider the number of the pieces there and the fact that their movements are "unstable" (as in not keeping the trajectories that are always at the same distance from the Earth).
Only once you understand all that read about:
https://orbitaldebris.jsc.nasa.gov/
The faq says:
> More than 21,000 orbital debris larger than 10 cm are known to exist. The estimated population of particles between 1 and 10 cm in diameter is approximately 500,000. The number of particles smaller than 1 cm exceeds 100 million.
Don't forget that these tiny fragments can cause significant damage.