The long-controversial notion that there's an as-yet-undiscovered “ninth planet*” has had a boost from the best kind of science: a prediction of its effects, borne out by observation.
The boffins that re-opened the debate in January this year, Caltech's Konstantin Batygin and Mike Brown, are feeling vindicated after a presentation (video below story) by astronomer Michelle Bannister at the SETI Institute.
That presentation included a slide showing an as-yet-uncatalogued Kuiper Belt object (KBO) with an alignment Batygin and Brown say fits with their predictions.
Brown and Batygin had previously used KBO alignments as the basis of their inference that something with about ten times Earth's mass lies behind their highly eccentric orbits.
If Brown and Batygin are right, the new planet would have an orbit so distant (75 times further from the Sun than Pluto) and elongated it needs between 10,000 years and 20,000 years to complete.
The new KBO was found by the Outer Solar System Origins Survey (OSSOS) using the Canada France Hawaii telescope.
Hey Planet Nine fans, a new eccentric KBO was discovered. And it is exactly where Planet Nine says it should be. pic.twitter.com/oZn0RDq8JF— Mike Brown (@plutokiller) March 24, 2016
There's still room for doubt. As New Scientist reports, California's Lick Observatory's Greg Laughlin says the new object can't be regarded as conclusive proof of “planet nine” unless its orbital inclination (that is, the orbit relative to the plane of the solar system) also matches the theory. ®
*Bootnote: Yes, Pluto-fans, we know that you'd prefer it were called the “tenth planet”. Argue about it in the comments. ®