^
That's my currently-favored explanation. Assuming its discovery was tied to a similar outburst over a century ago, it just seems a little too convenient for two significant impacts to have that kind of dramatic effect in that period of time.

In short, I'm thinking 17/P is a much more dramatic analogue of 29/P (Schwassman-Wachmann 2), which undergoes regular outbursts as well. Of course, it doesn't help that we don't know the cause of those, either...

__________________
"Call me old-fashioned, but I think fire is magic. And it scares me a lot."

--The State