Planet Nine Could Be A ‘Rogue’ World Captured By The Solar System

New data suggests that the mysterious and elusive Planet Nine, that theorized planet lurking out beyond little Pluto and believed to be the cause of perturbations in the orbits of a number of the Solar System’s denizens, could be a rogue planet captured by the immense gravitational pull of the Sun and its train of planetary followers as it wandered through the Milky Way.

Space.com reported January 10 that a new study has found that the still undiscovered Planet Nine, if it exists, could very well be a rogue planet. Using 156 computer simulations, James Vesper, an undergraduate at New Mexico State University (NMSU) and his mentor, math and physical science professor Paul Mason (also of NMSU), found that “it is very plausible” that Planet Nine was once rogue and was pulled into the Solar System as the two passed each other in space.

Vesper, the lead author of the study, presented the findings at the 229th meeting of the American Astronomical Society in Grapevine, Texas, on January 6. He noted that 40 percent of the simulations showed that a rogue planet became part of the Solar System in what he referred to as a “soft capture,” a planetary assimilation process whereby no native planets to the Solar System are ejected, or where the intruding rogue might kick one or more worlds out of the system’s alignment as it moved in. This was dependent on the rogue’s characteristics, he said.

The “soft capture” process, the simulations found, was surpassed by the more disruptive type of encounter, however. In 60 percent of the simulations, the rogue world would be hurled from the solar system in what Vesper referred to as a relatively simple “rogue in, rogue out” affair. Of that 60 percent, though, 10 percent of the simulations depicted the rogue taking at least one of our Solar System’s native planets with it as it exited.

The simulations showed that the likelihood of the Solar System ever encountering a rogue planet larger than the size of Pluto was highly unlikely. This is supported by the orderly and rather cohesive way the inner planets of the Solar System appear today, Vesper said. A rogue world larger than Neptune passing by would have likely been a disruptive force on the smaller planets in the Sun’s train.

As it stands, Planet Nine is still believed to be far larger than Earth with about 10 times the Earth’s mass. By comparison, the aforementioned Neptune is roughly 17 times Earth’s mass.

Although the existence of Planet Nine has been posited for decades (if not centuries), the first serious treatment of its possible existence came in 2014, when astronomers Scott Sheppard of the Carnegie Institution for Science in Washington, D.C. and Chadwick Trujillo of the Gemini Observatory in Hawaii proposed that its presence would explain certain oddities in the orbits of far-orbiting bodies like the dwarf planet Sedna. However, the two did not label the unseen force other than to refer to its a giant “perturber.”

Sheppard and Trujillo’s work was followed by that of Konstantin Batygin and Mike Brown of the California Institute of Technology in Pasadena, who, in 2016, found additional anomalies in the orbits of several more bodies in the outer Solar System. Batygin and Brown gave the cause of those perturbations a name; Planet Nine.

As Scientific American reported, astronomers Yuri Medvedev and Dmitri Vavilov at the Institute of Applied Astronomy of the Russian Academy of Sciences, added their study to what could be increasing evidence of Planet Nine’s existence. After studying the orbital paths of 768 comets, the duo noted that the odd paths of five of the comets were anomalous and “maybe Planet Nine made these comets go into the solar system.”

The search for the elusive world has been narrowed in the intervening months to a smaller section of the sky, according to a separate Space.com report, providing astronomers hope that the discovery of Planet Nine could be made in 2017.

[Featured Image by Vadim Sadovski/Shutterstock]