One of the scientists responsible for Pluto’s demotion from our solar system’s ninth planet to dwarf planet status says that there may be nine planets, after all.
Astronomer Mike Brown and his colleague Astrophysicist Konstantin Batygin, both of the California Institute of Technology, published a paper on Wednesday in the Astronomical Journal detailing evidence for a giant planet in the solar system.
They call it Planet Nine and, if it exists, it has a mass 10 times that of Earth and takes 10,000 to 20,000 Earth years to circle the sun, according to Brown and Batygin’s calculations. For comparison, Neptune, the (perhaps until now) farthest flung planet from the sun, travels around the sun in 165 years.
“In more than 150 years, we have the first observational evidence that the planetary census of the solar system is incomplete,” said Batygin. He also noted that while he and Brown were initially skeptical of the existence of Planet Nine, they have become increasingly convinced by their thorough research and calculations that it is indeed out there.
The road to their theoretical discovery began when Brown read a study by Chad Trujillo and Scott Sheppard that noted that 13 of the most distant objects in the Kuiper Belt — a region of the solar system beyond Neptune — are similar in the respect that they share an obscure orbital feature.
The authors of the paper explained the similarity by suggesting the presence of a small planet. Brown did not believe that explanation to be likely, but his curiosity was nonetheless piqued.
He took the problem down the hall to Batygin and for over a year the two investigated the distant objects, six of which traveled in an orbit at first baffling to the two scientists.
However, the more they crunched the numbers and ran computer simulations to understand how such objects could move together, the more convinced they became that a massive planet was not just possible but likely.
“This would be a real ninth planet,” Brown said. “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.”
If they are able to determine that Planet Nine exists, the discovery could shed important light on the solar system’s turbulent early years and help explain why the solar system looks the way it does today.
Image Credit: Caltech/R. Hurt (IPAC)