If our solar system has a “Planet Nine,” it would explain more things than if there were no “Planet Nine.”
A recent NASA report said that one scientist on the forefront of the search for hypothetical planet thinks the evidence is stacking up to prove that there is indeed an object between five and 20 times the size of Earth, but out past Neptune.
“There are now five different lines of observational evidence pointing to the existence of Planet Nine,” said Konstantin Batygin, a planetary astrophysicist at Caltech. “If you were to remove this explanation and imagine Planet Nine does not exist, then you generate more problems than you solve. All of a sudden, you have five different puzzles, and you must come up with five different theories to explain them.”
Batygin and Caltech astronomer Mike Brown wrote a paper in the Astronomical Journal in 2016 illustrating three of the five pieces of evidence positing the ninth planet’s existence. Much of it comes down to gravitational effects on the other objects in the solar system.
Here are the five things:
One: Beyond Neptune and before interstellar space have been found so far six objects, known as Kuiper Belt Objects, that all have the same eliptical orbit around the sun.
Two: Those objects’ orbits are roughly 30 degrees off the orbital plane of the eight planets from Mercury to Neptune.
Three: Computer simulations that included the hypothetica ninth planet suggested that there should be more distant objects in space that are off the plane of the planets, as much as 90 degree off the plane, and five known objects in space already fall within that parameter.
Four: The plane of the eight planets from Mercury to Neptune is also tilted, about 6 degrees from the sun’s equator. A second article from Batygin’s graduate student, Elizabeth Bailey, suggests this tilt could have been caused by “Planet Nine” over the last 4.5 billion years.
Five: There are distant objects in the Kuiper Belt that orbit the sun in an opposite direction than the planets. The orbital influence of a ninth planet would explain this, meaning the ninth planet that could be 20 times farther away from the sun as Neptune, caused these contrarian orbiting objects to fall out of a planar orbit, but then pulled back into a new orbit by Neptune.
“No other model can explain the weirdness of these high-inclination orbits,” Batygin said. “It turns out that Planet Nine provides a natural avenue for their generation. These things have been twisted out of the solar system plane with help from Planet Nine and then scattered inward by Neptune.”
The original paper played up the parameters of just where the ninth planet would be citing computer simulations. Those parameters have defined the search, which the team has been doing using the Subaru Telescope at Mauna Kea Observatory in Hawaii.
Continued simulations, the paper said, would further limit the massive search area to the eventual planet’s discovery.
In fact, the simulations since the initial paper’s publication in January 2016 have led the Batygin and Brown team to lean toward a planet that is about eight times the size of Earth and closer to the sun that previously posited, according to a report from the Washington Post.
“I’m just going to tell you: It’s there,” Brown told the Post.
NASA has also jumped on board the search for the elusive hypothetical planet by opening up images from the Wide Field Infrared Survey Explorer (WISE) spacecraft. Tens of thousands of volunteers from around the world look at flipbooks of images from the spacecraft taken over long periods of time to try and spot images in space that jump out.
The project titled “Bayards Worlds: Planet 9” at https://www.zooniverse.org/projects/marckuchner/backyard-worlds-planet-9 that launched in February has yet to find the hypothetical planet, but has revealed the existence of a brown dwarf (too big for planet, too small for a star) that is about 100 light years away from the sun. That one, co-discovered by four citizen observers, has been verified and published, and as of May 2017, 12 more brown dwarf candidates had been submitted for further observation.
The search for the ninth planet, though, continues.