In 1178 Gervase of Canterbury reported seeing a bright flash on the Moon and some researchers believe that a crater called Bruno on the far side was the result, but doubt has been cast on that belief. Multiple witnesses, fresh crater where they described the impact. They reported a phenomenon that conflicted with everything they knew about the perfection on the heavens. No reason to lie, and every reason to reject what they saw. What's to doubt?
If it had struck the Earth such an impact would have caused the destruction of a large metropolitan-sized area.
I wonder where this asteroid would fit on this scale?
By the way, this is strikenly similar to the homeland threat chart.