[1004.4584] Persistent Evidence of a Jovian Mass Solar Companion in the Oort Cloud.
John Matese & Daniel Whitmire discuss more evidence for a possible supra-Jovian somewhere in the Oort Cloud – they pin down a possible region to search, which WISE should be able to do as part of its all-sky IR imaging mission. We might know more in a few years time once the data is all in and confirmed by other scopes.
Of course the evidence for ‘Tartarus’, my hypothetical mini-Jovian/Ice Giant/Hydrogenated Supra-Ganymede, is independent of the Oort Cloud. But the migration events of the later stages of planet formation tossed both worlds into their present icy exile.
An alternative cosmogony is Edward Drobyshevski’s “Failed Binary” model, in which thousands of Moon-sized “Ganymedians” formed around Proto-Jupiter, helping disperse its mass, form the other planets, and populate the Oort with thousands of potentially terraformable worlds. The trick, as always, is finding the damned things in the Deep Dark.