RE:" by being misquoted. But then, of course, this has happened before, and quite "recently" at that"

It's really quite amazing how often you claim summaries of your comments are misquotes when no quote was claimed. This also occurs when logical extensions of your arguments are made to show they are incorrect. Again its not a quote. These are plainly interpretations of you position. If wrong, clarify don't slander.

Everyone interprets the intent and meaning of everyone else's post. You are one of the few people here who I think intentionally misrepresents the positions of others. Perhaps if you didn't do it so often yourself you wouldn't be so suspicious of others. I could be wrong though, you may just have a hard time understanding what everyone else is trying to say given that most have more technical training than you and can distinguish between engineers, technicians, and astronomers.

acase in point:
RE: "The populaton refered to by Morrison was that of all near Earth asteroids, and more than occasionally they do come in and not go back out."

You appear to be confusing near Earth asteroids with near Earth comets. Asteroids seldom do not return except for the rare close pass to Jupiter, the sun or an exremely close terrestrial planet flybye. Even NEC's usually return albeit at much longer intervals. Statistically speaking the exceptions are unimportant. Morrison understands this when calculating his odds.

RE: http://www.habitablezone.com/space/messages/22861.html

The global killers are a more significant threat despite lower frequency precisely because it doesn't matter where they hit, they will cause large scale death and destruction. The destructive power of impactors rises faster with diameter than their frequency decreases up to the global calamity threshhold. Frequency is roughly inversely proportional to diameter squared while impact energy is proportional to diameter cubed.

Regards,
Mark