(NEW YORK) — Researchers at the California Institute of Technology say they believe they have discovered a ninth planet within our solar system.
The object would be about 10 times the mass of Earth and orbit the Sun at a distance of 20 times farther than Neptune. A full trip around the sun, the researchers say, could take “Planet Nine” 10,000 to 20,000 years.
“This would be a real ninth planet,” said Mike Brown, a professor of Planetary Astronomy at Caltech. “There have only been two true planets discovered since ancient times, and this would be a third. It’s a pretty substantial chunk of our Solar System that’s still out there to be found, which is pretty exciting.”
The researchers say they haven’t directly observed the planet yet, but believe it exists based on the way other distant objects have been seen to move.
Brown told BBC News that “the most distant objects [in a band of distant material known as the Kuiper Belt] all swing out in one direction in a very strange way that shouldn’t happen, and 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.”
Copyright © 2016, ABC Radio. All rights reserved.