what was the closest time a astroid hit the earth

Question: what was the closest time a astroid hit the earth
- Keywords:
  astroid
Asked by Girl magnet to Mark on 10 Nov 2016.
- Mark Kennedy answered on 10 Nov 2016:
  
  The Earth is constantly bombarded by very small meteorites, which look like shooting stars across the night sky.
  
  As for big impacts, the most recent one I can think of is the Chelyabinsk event in 2013 (https://www.youtube.com/watch?v=dpmXyJrs7iU).
  
  As for impact events that caused mass extinction, that was most likely the Eltanin impact, around 2.5 million years ago (https://en.wikipedia.org/wiki/Eltanin_impact)

Question: what was the closest time a astroid hit the earth