“If you say, ‘We have evidence for Planet X,’ almost any astronomer will say, ‘This again? These guys are clearly crazy.’ I would, too,” said co-author of the study Mike Brown. “Why is this different? This is different because this time we’re right.”
The story of “Planet X” is a long one. Time after time scientists have put out studies claiming to have evidence for a new outer planet, but none have come to fruition. But now a group of scientists truly believe they have found firm evidence for a ninth planet of the Solar System, way beyond the orbit of Neptune. The planet, estimated to be about ten times more massive than Earth, orbits around twenty times further out from the Sun that the current outermost planet Neptune does.
Mike Brown and Konstantin Batygin, researchers at the California Institute of Technology (Caltech), have produced a study that concludes that “Planet X” probably exists. The strong belief they have that such a planet orbits on the outskirts of the Solar System is based on models produced of Kuiper Belt Objects and their orbital properties.
The Kuiper Belt is an icy region of the Solar System beyond the orbit of Neptune. There are six Kuiper Belt objects in particular that researchers are focused on, one of which being the minor planet Sedna. The objects all orbit the Sun in elliptical paths of the same direction, and share the same 30 degree tilt relative to the plane of the planets of the Solar System. It is believed the odds that this is purely a coincidence is 0.007%.
“Basically, it shouldn’t happen randomly,” said Brown. “So we thought something else must be shaping these orbits.”
“We realised the only way we could get them to swing in one direction is if there is a massive planet, also very distant in the Solar System, keeping them in place while they all go around the Sun,” explained Brown.
However, planetary scientist David Jewitt believes this not to be the case. The renowned professor of astronomy says that a 3-sigma percentage based on just six KBOs strongly weakens their case.
“I worry that the finding of a single new object that is not in the group would destroy the whole edifice,” says Jewitt, who is at UC Los Angeles. “It’s a game of sticks with only six sticks.”
Regardless, Brown and Batygin now believe that they have a rough idea as to where to look for the mysterious planet. No doubt, in the next few weeks, months and years astronomers around the world will be pointing their telescopes towards this region of the sky in the hunt for the ninth planet.
“There are many telescopes on the Earth that actually have a chance of being able to find it,” said Brown. “And I’m really hoping that as we announce this, people start a worldwide search to go find this ninth planet.”
Indeed, Brown and Batygin plan to also join the hunt using Japan’s Subaru 8-meter telescope based in Hawaii. The telescope has the light-gathering ability to detect an object as faint as “Planet X” and has an enormous field of view, ideal for covering large areas of the night sky. Brown believes that it will take around 5 years for a full scan on the region to be completed.
Primary source: http://iopscience.iop.org/article/10.3847/0004-6256/151/2/22/meta