https://phys.org/news/2018-05-space-junkavoiding-catastrophe-falcon-telescope.html

Satellites, discarded rocket bodies and other debris orbit Earth, kept close by our planet's gravitational pull. In 2013, NASA estimated that more than half a million bits of stuff surround Earth.

And with small satellites now being sent up to space in big numbers, it's looking to get a lot more crowded up there.