The white dots in the graphic above represent a orbital garbage in the Low Earth Orbit that NASA is tracking.
ScienceNews has posted an article explaining how the trash is monitored and why it can be really dangerous as most pieces are flying at more than 20 times the speed of sound. An example is a piece of trash the size of a tiny marble can have as much energy as a bowling ball going at about 805 kilometres per hour.
(via Boing Boing)