Planet Nine: Scientists Find ‘Solid’ Evidence Of Super-Earth Planet Beyond Neptune

Researchers at California Institute of Technology have found new evidence of the existence of a ninth planet in our solar system that they described as a “super-Earth.” The latest findings come three years after the same team proposed for the first time the idea of Planet Nine.

The study shows new details about the potential nature and location of the planet. Researchers initially proposed that gravitational tugs of an unseen planet have been causing the clustering of objects in the Kuiper Belt, just beyond Neptune, EurekAlert reported.

The team used thousands of computer models of the dynamical evolution of the distant solar system for their new report. The paper states that Planet Nine has a mass of about five times that of the Earth and has an orbital semimajor axis in the neighborhood of 400 astronomical units, which means it is closer to the Sun than previously reported.

Mike Brown, author of the report and a professor of Planetary Astronomy, said their latest data “indicate that the hypothesis rests upon a solid foundation."

"At five Earth masses, Planet Nine is likely to be very reminiscent of a typical extrasolar super-Earth," Konstantin Batygin, an assistant professor of Planetary Sciences, said. 

He added the unknown planet may serve as the solar system's missing link of planet formation.

“Planet Nine is going to be the closest thing we will find to a window into the properties of a typical planet of our galaxy," Batygin said. 

Batygin and Brown presented their first evidence of Planet Nine in 2016. Their initial report sparked a global effort by astronomers to search for observational evidence of the new planet.

However, the two researchers admitted they still have doubts that the planet actually exists. But they noted they will continue to examine the orbital dynamics of the solar system to get stronger evidence.

"My favorite characteristic of the Planet Nine hypothesis is that it is observationally testable," Batygin said. "The prospect of one day seeing real images of Planet Nine is absolutely electrifying. Although finding Planet Nine astronomically is a great challenge, I'm very optimistic that we will image it within the next decade."