Five-planet Nice model distant massive ninth planet is responsible for the alignment of the perihelia of several trans-Neptunian objects with semi-major axes greater than 250 AU. Although the mechanism for the ejection of the fifth giant planet in the five-planet Nice model is reminiscent of the origin of Planet Nine, with a gravitational instability including an encounter with Jupiter, it is unlikely to be the same planet. The estimated timing of the capture of Planet Nine onto its distant orbit, three to ten million years after the formation of the Solar System, when the Sun was still in its birth cluster, is inconsistent
The Fifth Season (novel) The Fifth Season (novel) The Fifth Season is a 2015 science fantasy novel by N. K. Jemisin. It was awarded the Hugo Award for Best Novel in 2016. It is the first volume in the "Broken Earth" series and is followed by "The Obelisk Gate" and "The Stone Sky". "The Fifth Season" takes place on a planet with a single supercontinent called the Stillness. Every few centuries, its inhabitants endure what they call a "Fifth Season" of catastrophic climate change. The society of the Stillness is broken up into many "comms", "use-castes", races and species. Use-castes: In a prologue, an