Astrophysicists have long wondered why our sun is tilted at a different angle than the rest of the known solar system. While all eight known planets rotate on a flat plane within only a few degrees of one another, the sun itself appears to be tilted roughly six degrees off of the planets. Now, new research shows that a massive, undiscovered ninth planet at the edge of the solar system might actually be causing the other planets to “wobble” in their orbit around the sun.
This isn’t the first time scientists have speculated about the existence of “Planet Nine” – earlier this year researchers from Caltech predicted its existence due to the abnormal bunching of several objects orbiting near Neptune, an effect which could only exist if a large, unknown planet were exerting a gravitational influence. Planet Nine has yet to be observed directly, but more and more evidence is beginning to point to its existence as the answer to some of our solar system’s enduring mysteries.
If you’ve never heard about the fact that the planets are slightly off-kilter compared to the sun, you’re not alone. Mike Brown, one of the authors behind the Planet Nine theory, explains, “It’s such a deep-rooted mystery and so difficult to explain that people just don’t talk about it.”
The as-yet unseen planet is estimated to be about 10 times the size of Earth, with an orbit 20 times farther from the sun than Neptune. It also appears to orbit about 30 degrees off of the orbital plane of the rest of the solar system – an angle that, along with its massive size, could be slowly pulling objects within the solar system off-balance. That’s not too surprising, considering scientists believe Planet Nine might eventually destabilize the solar system once the sun balloons into a red giant.
What is still unknown is exactly how Planet Nine came to occupy its unusual orbit in the first place. It’s possible it may have once sat with the gas giants near Jupiter before being ejected. The gravitation pull of other stellar bodies might have also had an influence at some point in the solar system’s distant past.
The new study will be published in an upcoming issue of Astrophysical Journal.
Images via Caltech