I ran across another off-air comment, this one about the crumbly SW3 comet, which asserted that because it hyped around Sol every 5.4 years (and so — in principle — erodes and decomposes very rapidly), SW3 was “very unlikely” to have lasted as it was for as long as 100,000 years.
I haven’t studied all of the ramifications, but prima facie the commentator appears to be correct.
This will not, however, be a path to communal happiness for the commentator since the orthodox view of comets is that they’ve all been around for roughly as long as the Solar System, a value typically given as roughly [AFAICT, weren’t no stopwatches etc available at the time, whenever it actually was] 4.5 billion years. If he wants his conclusion accepted, the battle is going to be very much 100% uphill — but if successful, SW9 will be very much a shortbread (or shortglow, shortflash — whatever).
There appear to be two more-or-less orthodox schools of thought on these few billion years, one claiming that comets bounce around more or less arbitrarily and another that treats the Oort Cloud as a kind of storage facility for excess comets. According to what I see pro and con, they may each be partially or completely right; sooner or later, some serious little spacecraft are going to buzz through the outer Solar System with their (presumably electronic) eyes wide open, and provide more definite answers.