The scientific world is still abuzz with speculations as to where exactly one can find the elusive Planet Nine, which was hypothesized as the ninth planet of the solar system as of January last year. Its origins now appear to be far more exotic than previously thought.
Planet Nine could be a “rogue planet” — a free-moving body not bound to any specific star — in the past, which eventually got snatched into the solar system through the sun’s gravitational pull, according to findings from New Mexico State University researchers.
This is highly plausible, said lead author James Vesper last Jan. 6 during a media conference at the American Astronomical Society’s 229th meeting in Texas.
“[Rogue planets] have been predicted to even outnumber stars by a large fraction, and may partially account for dark matter in the disk of the galaxy, as the result of circumbinary planet formation,” read the study abstract.
What Happens To Rogue Planets In Our Neighborhood?
Vesper and his professor Paul Mason made computer simulations of 156 encounters shared by the solar system and rogue planets with varying sizes and trajectories. These are hardly uncommon encounters, as previous research indicates that there are actually more rogue planets than “normal worlds” revolving around their stars in the Milky Way.
Their findings showed that most of the time, the rogue planets would likely be ejected by gravitational forces in the solar system, while in around 10 percent of the cases, the departing body would take an existing planet in the solar system with it as it leaves.
For around 40 percent of the time, though, the planet would get pulled into the solar system through a so-called “soft capture” or with the ejection of a native planet, depending on the rogue’s abilities.
Astrophysicists Michael Brown and Konstantin Batygin from the California Institute of Technology proposed the potential existence of Planet Nine in January 2016, noting specific gravitational anomalies in the outer solar system that could possibly be explained by a huge planet loitering outside the solar system’s observed reaches.
Planet Nine is believed to be about 10 times bigger than Earth.
Other Perspectives
For Northwestern University professor Michael Smutko, who was not part of the study, the new explanation is rather unlikely.
In an email to the Christian Science Monitor, he envisioned the sun as orange or apple-sized, and the planets as fruit flies buzzing around it. Given this scale, Proxima Centauri — the next closest star to the sun — would emerge as another fruit about 1,400 miles far, about the distance from Chicago to Tucson.
“Now imagine the chance of a fruit fly in Chicago making its way 1,400 miles and finding the apple in Tucson. It could happen, but it's not the way to bet,” Smutko explained, preferring the theory that the planet formed alongside other planets in our part of space.
Today, astronomers are yet to prove the planet’s existence, fueling more excitement and speculation around the widely discussed mysterious world. Planetary sciences, for one, continue to challenge research, partly in light of the demotion of Pluto into a dwarf planet back in 2006.
