The Russian meteor, and other such jargon

We'll I think we've all seen something about the meteor that came crashing down to earth and making impact in Russia.  So, we've done a little research and found out our knowledge for the day.

On average around 40,000 impacts occur on earth per year.  Most are not noticed, but occasionally can produce recoverable meteorites.  However, the percentage that are large enough to produce craters is very small indeed.  Approximately 150 know craters have been produced by meteoric impacts. The largest of which is a crater know as the Vredefort Dome located in South Africa.
  So...
  There you go, feel free to add, comment, edit, elaborate.
-Thomas