No idea. I hadn't considered anything like that. It was just a GCSE thing I did in my very early 20s for fun (already had an O level from school), and I was specifically looking at Titius-Bode for the main part, then the Drake equation towards the end.
The point was that Titius-Bode works as an approximation until you hit Neptune for the ninth position (the fifth is Ceres/the asteroid belt) - and then, of course, Pluto is wrong for the tenth.
Take Neptune out though, and Pluto is in the right place for the ninth value in the sequence - so I suggested Neptune didn't originate hereabouts. (If memory serves, I suggested that its arrival could be one explanation for Uranus' axial tilt - not as an ongoing thing, but simply that it had an effect when it came too close, before finding itself in a more stable orbit.)
The two distances in my previous post are therefore 10th and 11th.
Edit: I think I may also have suggested it caused a larger body in fifth position to break up and become the asteroid belt - though these days I believe the consensus is that there isn't enough material there for it to have formed a planet to start with.
OTOH, perhaps that's because the missing material ended up scattered more widely, and some of it may have been the material in the bombardment. And if this theorised new planet has such an odd orbital plane, maybe it caused that as well. :)
Edit again: I found the file with that coursework on a while back, but didn't have the right software to read it. I do have the software now, so just need to find the file again. It'd be fun to read it again, and perhaps tidy it up/shorten it - and if necessary fix some of the out of date info - and throw it on my blog or something.
Biting the hand that feeds IT
