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 Secret of the Ninth Planet Plutonians dead, the danger to the solar system is past. Burl sees then the people of other planets and of other stars coming together in peace and mutual understanding. The book was reviewed by “When the power of the sun becomes noticeably diminished, young Burl Denning and his expedition take off in an anti-gravitational ship to discover the cause and its location. After a dizzying tour of all the planets, they realize that the trouble springs from Pluto, a belligerent planet which is trying to usurp the life-giving power which the sun gives earth. Making an alliance with the friendly