What really interests me is the discussion on the nature of the impactor. My money is on a comet. If you look closely at Anthony's image you can see two little spots at thefour o clock position to the main spot.
Indeed ... but given that the impact mark is so large, by comparison with SL9 we're talking about a 1 Km +, possibly 2 Km diameter object; I think a "fresh" comet would have some sort of tail if it were out by Jupiter and should have been detected long since. Don't forget that, the more we look at even small asteroids, the more we find have small satellites.
The news media seem to be studiously avoiding reporting this event, not even a whisper on e.g. the science page on the BBC News site.
