Synopsis
This research paper investigated the possibility of an Earth-like planet in the distant Kuiper Belt, a region of the solar system beyond Neptune. They used N-body computer simulations to study the effects of a hypothetical Kuiper Belt planet (KBP) on the orbital structure of trans-Neptunian objects (TNOs) beyond ~50 astronomical units (au). The researchers found that an Earth-like planet with a mass of approximately 1.5-3 Earth masses, located on a distant and inclined orbit (semimajor axis between 250-500 au, perihelion around 200 au, and inclination around 30°), could explain three fundamental properties of the distant Kuiper Belt: a prominent population of TNOs with orbits beyond Neptune’s gravitational influence, a significant population of high-inclination objects, and the existence of some extreme objects with peculiar orbits, such as Sedna.
The proposed KBP is also compatible with the existence of identified gigayear-stable TNOs in various Neptunian mean motion resonances. The study predicts the existence of an Earth-like planet and several TNOs on peculiar orbits in the outer solar system, which can serve as observationally testable signatures of the putative planet’s perturbations.
