Mike Brown and Konstantin Batygin (astronomers from the California Institute of Technology) announced they have conjectural evidence for the existence of a ninth planet in our solar system.
Details were published in the newsmedia, in the Caltech website ("Caltech Researchers Find Evidence of a Real Ninth Planet", by Kimm Fesenmaier, Jan. 20), and in the Science magazine website ("Astronomers say a Neptune-Sized Planet Lurks Beyond Pluto", by Eric Hand. Jan. 20).
As in the case of the discovery of Neptune (mentioned in the video and about which I write in "Observation vs Deduction"), Brown/Batygin's conjecture is based on anomalies observed in the orbits of existing astronomical bodies and requires observational (empirical) confirmation.
If Planet X -- whose existence has been deduced -- is found, that would explain those anomalies.
It should go without saying -- but I will say it anyway -- a failure to find such planet (an incredibly difficult task, given the volume of space involved) would be terribly embarrassing to Brown and Batygin, although in fairness, given the difficulties, perhaps it would be less than fatal. It would also have implications against the theoretical framework they employed: if not Planet X, what on earth explains those anomalies?
That, however, is obvious and is not what drives me to post.
What drives me to post is that cases like this seem not to fit well in Sir Karl Popper's simplistic scheme (scheme which was enthusiastically adopted by Joan Robinson). I've written about this before and there's no point repeating myself. Those interested please read "Popper, Art, and Science".