More Debris Makes More Debris
There’s a pretty awesome entry at the Long Now blog about the Kessler Syndrome, defined by Wikipedia as “a scenario, proposed by NASA scientist Donald J. Kessler in a 1978 publication, where the volume of space debris in Low Earth orbit is so high that objects in orbit are frequently struck by debris, creating even more debris and a greater risk of further impacts.”
Apparently there’s a lot of trash floating around in space, crashing into other trash, creating more trash. Here’s a video model of what happens and photos of hyper velocity impacts.