Jason Snell | Yahoo Tech | January 20, 2016
(Image: Caltech/R. Hurt (IPAC))
A decade ago Mike Brown helped get Pluto demoted from a “planet” to a mere “dwarf planet.” Now the astronomer and one of his CalTech colleagues may have plotted the orbit of a new ninth planet in our solar system, dramatically larger than Pluto and much, much farther away.
As described by Brown and fellow astronomer Konstantin Batygin Wednesday in the Astronomical Journal, this new planet would be roughly 10 times the size of the Earth and would take as much as 20,000 years to make a single orbit around the sun. Its theoretical size — between the size of the Earth and Neptune — is unlike any other body in our solar system, but fits into the most common size of exoplanets detected in other systems.
Astronomers have been hunting for an undiscovered “Planet X” for nearly two centuries, generally without success. The notable exception: Neptune’s presence in our solar system was predicted by observing irregularities in the orbit of Uranus — and then later proven by observation through telescopes. Brown and Batygin’s finding is similar, in that they’ve done the math that strongly suggests the presence of a large planet in an weird orbit way beyond Pluto. But until someone spots the planet with a telescope, it’s just a theory.