Colliding space junk makes 'noise' that could be heard from Earth 

 Weird effects of space junk collisions could help researchers detect dangerous, hard-to-see orbital clutter. 

https://cdn.mos.cms.futurecdn.net/naQtry7CedNEFLbjen6Rqe.jpg

https://www.space.com/colliding-space-junk-emits-detectable-signal