I wrote a Spacebit about the Fomalhaut system:
Imagine a bulbous ball of ice, rock, and metal that stretches at least 6 miles across moving at 85,000 miles an hour smashing into another bulbous ball of ice, rock and metal traveling at similar speeds. It would create an explosion that, if it were to happen in our atmosphere, would do some serious damage to our planet. Now, imagine this happening 2,000 times a day every day for millennia.
I had a lot of fun researching this piece.