Story 2016-09-03

Growing evidence supports the existence of a hypothetical Planet Nine

by
in space on (#1SJW7)
The case for Planet Nine's existence keeps getting stronger. Astronomers have discovered several more objects in the extreme outer solar system whose orbital characteristics hint at the existence of an unseen "perturber" in the dark depths far from the sun - a hypothetical world larger than Earth that scientists are calling Planet Nine. "If you want to put a number on it, I'd be somewhere like 80 percent sure that there's a Planet [Nine] out there," said Scott Sheppard.

In their 2014 study, Sheppard and Trujillo noted that several extremely distant objects share certain orbital characteristics, and suggested that these bodies' paths around the sun may have been shaped by a large planet in the region. This hypothesis was bolstered earlier this year. Computer simulations suggested that the gravitational influence of a roughly 10-Earth-mass planet about 600 AU from the sun could indeed explain the odd "clustering" in the orbits of Sedna, 2012 VP113 and a handful of other distant objects.

Finding Planet Nine via a blind search would be incredibly difficult and time-consuming. The putative world, while big, would also be quite faint because of its immense distance from the sun. The planet's huge and as-yet-undetermined orbital path also means it could be hiding anywhere along a large swath of sky. But Mike Brown of the California Institute of Technology has said that Planet Nine may well be visible through powerful telescopes, provided astronomers point them in the right direction at the right time.