Re:‘Goblin’ world found orbiting at the edges of the Solar S...
by autocorr on Tuesday October 02, 2018 @06:30PM
(#18126258)
Yes, I agree, it's a combination of high inclination, perihelion, and eccentricity that point point to scattering.
The clustering of the arguments of perihelia is less straight forward (you can see it in Figure 4 of the linked pre-print PDF in another comment) and my limited understanding is that they are shepherded into that configuration over time by the large body. That is more clear when you see the results of the numerical simulations I suppose.
Re:‘Goblin’ world found orbiting at the edges of the Solar S...
by sandworm101 on Tuesday October 02, 2018 @06:35PM
(#18126287)
The number of potential encounters is also a factor. Objects in orbits this large, with periods measurable in thousands of years, won't have many periodic encounters. There isn't enough time since the formation of our solar system for them to get close enough together. The lower the number of potential encounters, the more significant must those be that do happen. That too points to a larger body out there.
To get a significant inclination (ie away from the low inclinations of the inner planets) and a drop in the perihelion (ie highly oval rather than the round orbits of the inner planets) you need a close pass of a large body. As the little think comes close to the big thing it is thrown randomly, away from the nicely round orbits of most things in the early solar system. So if you find a body with those two features, you know it passed close to something big somewhere our near the highest part of its orbit. That is the evidence of a large object out beyond pluto.