vnangia

Which would you rather fight? One hundred cat-sized planets or one planet-sized cat?

Given the distances involved, wouldn't we see significant differences in the atmosphere at perihelion and aphelion? I got the sense from an NH briefing that even Pluto has a much thicker atmosphere closer to the sun than at aphelion and unless 9 is generating a lot of heat internally, isn't it likely the atmosphere freezes and falls to the ground? Kind of like Vinge's on-off star, now that I think about it.

Thanks Konstantin. I keep wondering if its analogous to the gaps in Saturn's rings with shepherd worlds.

Wish I'd done astronomy or cosmology when I had the chance. Alas.

Reading your paper, I didn't get a sense of whether 9 can explain the Kuiper Cliff. Can it? If not, what do you think is causing that, assuming it isn't observational bias?

My (non-scientist) understanding is that while a passing star could set it up that way, it wouldn't keep them there. You'd still need something like 9 to keep them in those orbits.