Look at the light coming off the far side of the sun post-impact.
It's almost unbelievable how an object "tens of meters" in diameter can affect an object nearly 1.4 Billion meters in diameter.
Just startling.
(Note, comets average 20k mph, so we're still talking maybe 2/1000th's of a percent of c, right? It's not like it's a relativistic bomb or anything... yet billions of meters away, a light burst nearly instantaneous upon impact.)