Upper stages of launch vehicles, defunct satellites, flecks of paint and other pieces of fast-moving space junk can all threaten active spacecraft. In 1996, a French satellite was damaged by debris from a rocket that exploded 10 years earlier, and a 2007 anti-satellite test launched by China introduced more than 3,000 pieces of debris to space, according to NASA.

As of Sept. 2013, NASA officials estimate there are more than 500,000 pieces of debris the size of a marble or larger orbiting Earth. More than 20,000 pieces of space junk are larger than a softball, but there are millions more that are too small to track, NASA officials have said.

I think that graphic is highly misleading. They should depict each dot as a Tralfamadorian danger zone hurtling faster than anything around and around in slightly different trajectories, but never actually burning up....it's a dangerous space out there. 

So open the link and watch the videos.  :)

500,000 is a lot of space debris!