Two satellites collided over Siberia in February 2009 producing significant amounts of orbital debris. I created this animated gif using this video posted by NASA APPEL.
Debris from the collision between Iridium 33 (green) and Cosmos 2251 (red) spread very quickly. These images show that within a few hours of the collision, the evolution of a debris cloud was already apparent along the orbital planes of both satellites.
NASA released a digital book if you’re interested in learning more about the risks of junk in space.
