dougettinger wrote:The Sun's gravity field is obviously significant to capture bodies for the Oort Cloud and continue to grasp them.
The Sun's gravity is not capturing bodies in the Oort cloud. These are simply bodies left from the formation of the Solar System that lacked the necessary velocity to escape. That is very different.
The combination of this same gravity field and the perturbations of the Oort Cloud itself should be enough to capture the same size bodies as they intersect the Oort Cloud from outside.
No. The solar escape velocity in the Oort cloud is on the order of a meter per second. Anything passing through the Oort cloud at greater than this will not be captured by the Sun. Anything passing through the region of the Oort cloud is extremely unlikely to be perturbed by the cloud itself, since it in only a few Earth masses distributed over something approaching a cubic light year. There is nothing there to capture anything.
From the perspective of an outside body, the Solar System is essentially the Sun and Jupiter, with a tiny influence from the remaining three gas giants. That's it. To be captured into a solar orbit, or into an orbit around a planet, that body will need to pass very close to an existing planet (or the Sun), and be diverted from there around another. This just isn't a likely scenario, and can't really happen for any object entering from off the plane of the system.
I believe you missed my point. I am not assuming that most bodies in interstellar space come from ejected denizens from forming star systems.
No, I didn't miss your point. I just disagree with your assumption that small bodies are formed in dust clouds. I don't think there is any evidence supporting that. I think that whatever small bodies exist in interstellar space originated in protostar systems. The gas density isn't high enough in molecular clouds to allow Pluto-sized bodies to form before stars form.