I was arguing with a friend of mine the other day about the Tunguska event in the early 1900′s. He says that a UFO crashed and I said it was a meteorite that exploded in the air. But then he told me that it left a radioactive trace behind. But it got me thinking, would a meteorite impact leave a significant amount of radioactivity.
P.S. I’m not looking for evidence of aliens. I’m only interested in astronomical facts.