It could be the first new planet discovered in the last 170 years — or at least the last 85, if you’re one of those stubborn folk who still insist on calling Pluto a planet.
Two Caltech astronomers, Mike Brown and Konstantin Batygin, have noticed some weird behavior in the outer solar system they think is caused by an unseen world orbiting roughly 500 times farther from the Sun than Earth does.
The evidence consists of a strange alignment of some so-called Kuiper Belt objects (KBOs) — ice-bound orbs that are cousins of Pluto. These oversized hailstones are strewn throughout the dim and distant nether regions of our solar system. Their discovery almost a decade ago led to Pluto’s loss of membership in the pantheon of planets. […]