Science Alert: According to de la Fuente Marcos and his fellow researchers – brother Raúl and Sverre J. Aarseth from the University of Cambridge in the UK – it's possible that the stability of these objects might instead be due to the gravitational pull of a number of undiscovered planets hidden somewhere on the edges of the Solar System, meaning Planet Nine could have company. by PETER DOCKRILL via SINC
'"That is to say we believe that in addition to a Planet Nine, there could also be a Planet Ten and even more," said de la Fuente Marcos.
'Not everybody is convinced by the new findings. Astronomer Mike Brown, one of the Caltech team who originally introduced the Planet Nine hypothesis, is critical of the new paper.
'"I think it's way too early to start speculating about a second planet, but, in general, I am confused by their results," he told Abigail Beall at the Daily Mail. "We have a nearly identical analysis which shows nearly the opposite result. It is not obvious to me why they would get such a different answer."'