During the last couple years there have been a few papers published showing that for the Nice model to produce our solar system Jupiter and Saturn had to be separated quickly. The solution offered for this issue was encounters between one of the ice giants and Saturn and Jupiter in turn, the first pushing Saturn out and the ice giant in and the second pushing Jupiter in and the ice giant out, thus increasing the separation of Jupiter and Saturn in two large jumps. This was referred to as the Jumping Jupiter Model. A problem with this model was when the ice giant encountered Jupiter it was often ejected.

A recent paper offers a solution to this problem: the solar system started with five giant planets, one of which was lost after its encounter with Jupiter.

Young Solar System’s Fifth Giant Planet?


ADMIN - Thread title edit to be less inflammatory and rule breaking

A long article (very well illustrated) is devoted in the latest Ciel & Espace(*) March issue about David Nesvorny's theory...
Also explaining the "Nice model" about how giant planets form.
And, finally, telling why Mars is so small and was depleted of materials to grow more because of Jupiter and Saturn outward migrations in a second step (the 1st step was their inward migrations)...
Enjoy !
Click to view attachment Click to view attachment


(*) Ciel & Espace is the biggest astromony magazine in France (the equivalent of "Sky & Telescope" in the US)

"Une planète géante éjectée du système solaire ?
L'hypothèse paraît incroyable. Elle est pourtant prise très au sérieux.
Le Système solaire aurait éjecté une planète géante il y a 3,9 milliards d'années.
Peut-être même deux planètes !
Pour convaincre, l'astrophysicien David Nesvorny ne manque pas d'arguments… "

PS : to "Admin" : Why "inflammatory" ? The title of this scientific article states exactly this : "Young Solar System’s Fifth Giant Planet ?". Warmest regards, VM

Jupiter's effect inward in the asteroid belt (Kirkwood gaps, etc.) being almost trivial in comparison to the effects outward. The word 'careening' kept springing to mind as I read the paper.

Appreciate the paper, and I note it's relevance in comprehending the weird and wonderful planetary systems Kepler is finding for us.