Today's Astronomy Picture of the Day shows the aftermath of powerful collision between two asteroids in the belt between Mars and Jupiter. They estimate the speed of the impact at "15,000 kilometers per hour -- five times the speed of a rifle bullet -- and liberated energy in excess of a nuclear bomb."
What Hubble saw indicates that P/2010 A2 is unlike any object ever seen before. At first glance, the object appears to have the tail of a comet. Close inspection, however, shows a 140-meter nucleus offset from the tail center, very unusual structure near the nucleus, and no discernable gas in the tail.
Link Photo: NASA/ESA/D. Jewitt (UCLA)
This was probably the energy of kilotons or at most megatons, but nowhere near the light or thermal intensity. No radioactive products either. The brisance was much lower, things did not fly away as fast or get vaporized as much.
"I'm beginning to agree with you. Chewie, see if you can get closer to one of the big ones!"