There are some basic facts you learn in early childhood. You learn about the four seasons. You learn about numbers, the alphabet, and the colors of the rainbow. You learn there exist seven continents on earth, and eight planets in our solar system.
But, scientists are beginning to push back on this last one.
For a little over a year, astronomers have been exploring the possibility of an elusive "Planet Nine" in the solar system. A new discovery of an asteroid that may be affected by "Planet Nine" provides more evidence to suggest its existence.
The asteroid, called 2015 BP519, was announced in a paper released last week on May 16. The abstract proposes, "We also consider the long term orbital stability and evolutionary behavior within the context of the Planet Nine hypothesis, and find that 2015 BP519 adds to the circumstantial evidence for the existence of this proposed new member of the solar system." Space.com details the paper's findings, saying researchers explain, "...[the asteroid's] bizarre angle of its orbit gives more weight to the idea that a big planet is out there — somewhere — tugging on the asteroid's path around the sun."
To understand the significance of the finding, let's consider what researchers are already theorizing about the elusive Planet Nine — which, surprisingly, is a lot, considering we haven't actually found it yet.
The proposition of Planet Nine's existence was announced on January 20, 2016, per Space.com. It is thought to be the size of ten Earths (keep in mind Earth is the fifth largest planet in the solar system, with a radius of 3,959 miles). It was proposed by Drs. Mike Brown and Konstantin Batygin, two scientists from the California Institute of Technology. According to Space.com, the team "used mathematical models and computer simulations to map out Planet Nine's orbit after spotting a strange alignment in the orbits of six other Kuiper Belt objects." Those models suggest that it exists in the Kuiper Belt— the circular region of space occupied by icy objects around the Sun. It would extend slightly beyond the orbit of Neptune, according to NASA, and would be between 10,000 and 20,000 years old, with an average surface temperature of negative 374.8 degrees Fahrenheit (!).
But of course, the kicker is the exact location of the alleged planet has never actually been found — leaving researchers with no choice but to draw conclusions based on the behavior of other objects in the solar system, like our new friend asteroid 2015 BP519.
So the evidence of this planet's existence is circumstantial. Supported by science, but circumstantial.
As with most unconfirmed findings, there is debate in the astronomical community about whether or not Planet Nine exists at all. A research fellow from Queen's University Belfast claims the observed phenomena may be attributed to diffusion.
There are, as of right now, at least five nearby object displaying these effects, according to scientists at the California Institute of Technology, Space.com reports. Dr. Batyan continues to support the finding, saying in a statement to NASA, "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."
It will likely be a long time before the existence of Planet Nine can be definitively confirmed or rebuked. But, the existence of the newfound asteroid, 2015 BP519, is clear as day — whether or not someone can find an alternative explanation for it that doesn't involve adding another Sailor Scout to the mix is yet to be seen.