"Think back to your childhood of a sooty snowball with a rock at its center... they weren't very nice to you then, now were they... but children can be so cruel... people as well.."

Was this a hidden jab at the OP? Of so, the OP will pretend he didn't hear that (hopefully that was just an example, and not a charged comment). ;o] Mercifully, nobody ever hid projectiles in their snowballs with me. Or if they did, I'm sure they got a bloody nose out of it afterward... Wait, I was never a kid, what are you talking about? Hehe. Anywho.

Gas, loose molecules... To-may-to, to-mah-to.

Very fine atom or molecule-sized bits...

I guess I'm still wondering about comets or asteroids crashing into one another. Since I've heard that is a theory of formation of larger asteroids, moons, planets in general. And they usually quote some kind of high-impact-melts both bodies theory where they just kind of melt together into one solid body. I'm just wondering if that's anywhere even close to accurate. I mean if we're basically saying that things are composed of loose molecules, or big ol' dust balls. Or barring that, big hard rocks...

Now, if you fire two rocks at each other from opposite directions. MY gut reaction says that if they're rigid bodies, they'll crash and bounce off each other or if fired hard enough they'll crash and shatter. Or if they're soft bodies they'll just go splat and fly apart from the combined energies of the two objects. Has it ever been demonstrated that comets, asteroids or other rigid bodies can hit other bodies and merge rather than shattering and flying apart?

And I just don't see one round-ish comet/asteroid gravitationally attracting another oe and somehow through basically no forces other than sitting next to each other they'll merge into another larger somewhat spherical object?

I don't doubt the part about broken up meteorites being "related" since they came from the same body initially. I see no reason why different parts of the same object should be substantially different prior to break-up.

I agree that break-up seems to not be a strictly volatile outgassing-to-the-point-of-explosion phenomenon. However, breakup does always seem to be a violent end with a bit of a bang, as it were, and there is generally a coma present at the time of breakup. So, it can't be a purely gravitational mechanism either or you wouldn't have coma generation in all cases. But there's usually a coma on the main comet/asteroid, and then when it breaks up there are individual comas on each of the pieces...

anyway, not really surewhere I going with it all. Just seems like some comets make it through the inner solar system none the worse for wear. And some of similar dimensions and apparent composition break up relatively far out without a particular notable reason.

Just all seems a bit mysterious. That and when classically classified "asteroids" start moving into the innards of the system and then magically "develop" a coma. It seems enigmatic. And it seems like maybe we either are mistakenly classifying some objects in one that should be in the other, or we're artificially dividing a group of objects that for all intents and purposes SHOULDN'T be divided 'cause they're the same thing (according to photographic records showing them to be distinctly similar structures with similar features, composition & size, minus slight differences perhaps in overall shape or very specific patterns of craters or other scars).