Astrophysicists from Kindai University and Japan’s National Astronomical Observatory, both in Japan, have found possible evidence of an Earth-like planet in the Kuiper belt. In an article published in the journal Astronomy Journal, Patrick Sophia Lykavka and Takashi Ito describe features of the Kuiper Belt that they believe are consistent with the existence of a planet not much larger than Earth.

Over the past decade, many studies have given credence to theories regarding the possible existence of a planet in the farthest reaches of the solar system, theoretically known as Planet Ninth. In this new study, the researchers suggest that there may be a much closer planet in the Kuiper belt.

The Kuiper Belt is a semicircular disk of objects that begins just beyond the orbit of Neptune in the outer Solar System. Like the planets, matter in the Kuiper Belt revolves around the Sun. Previous studies had shown that objects in the disk were asteroids, space rocks, comets, and other small pieces of material, possibly made of ice. In their study, the researchers found that some objects in the Kuiper belt behave in a way that indicates the presence of a minor planet between them, about 500 AU from the Sun. For comparison, Neptune is about 30 AU from the Sun.

While studying trans-Neptunian objects (TNOs), the researchers found that the orbits of some of them behaved strangely; which means they are affected by the gravitational pull of an object larger than typical TNOs. They also found a large number of objects with a large inclination (a large inclination of the orbit). Influenced by their findings, they ran a series of computer simulations designed to explain the behaviors they observed.

Modeling showed that the most likely explanation for their observation was the Kuiper belt planet. Simulations also showed that such a planet, if any, would have a mass of 1.5 to 3 times Earth, an inclination angle of about 30 degrees, and an orbit that would take the planet 250 to 500 AU from the ground. Sun.