"Nearly 70 years after the launch of Sputnik, there are so many machines flying through space, astronomers worry their light pollution will soon make it impossible to study other galaxies with terrestrial telescopes.
Then there is the space junk — nearly 30,000 objects bigger than a softball hurtling a few hundred miles above Earth, ten times faster than a bullet."
"The study found that 10% of the particles in the upper atmosphere now contain bits of metal from rockets or satellites falling out of orbit and burning up. As humanity becomes increasingly dependent on information beamed down from above, the report predicts manmade debris will make up 50% of stratospheric aerosols in coming decades, matching the amount created naturally by the galaxy."
"Ever since, “Kessler Syndrome” — depicted with appropriate suspense in the 2013 film “Gravity” — has been shorthand for the industry’s worry that too much space traffic will eventually create a vicious cycle of more debris leading to even more collisions until launches become impossible.
In low-earth orbit, objects can collide at around 23,000 miles an hour, enough for even the tiniest debris to crack the windows on the International Space Station."
https://www.cnn.com/...-scn/index.html
