Is this what Planet 9 looks like?

by Kermit Woodall

A sneak peek at what Pluto’s successor might look like

Possible interior structure of the hypothetical Planet 9(Credit: University of Bern)

If there is a ninth planet in the outer Solar System, what is it like and why hasn’t it been spotted yet? A possible answer comes from a pair of astrophysicists at the University of Bern, who used models developed for studying exoplanets to determine the structure of the hypothetical Planet 9.