Some scientists think there is a planet hiding in the distant frontiers of the solar system. This elusive world dubbed Planet Nine has not yet been found but astronomers already have an idea what it looks like.
In the new paper published in the journal Physics Reports on Feb. 10, researchers used new computer models of the dynamical evolution of the distant solar system to gain an updated insight into the nature of Planet Nine. Results suggest Planet Nine is probably five o 10 times as massive as Earth.
Planet Nine also likely travels along an elongated orbit that peaks at 400 times the distance between the Earth and the sun, which means it is smaller and closer to the sun than previously thought. It could also be brighter.
The researchers also think the orbit is 15 to 25 degrees off the main orbital plane of the solar system where most of the planets orbit.
“At five Earth masses, Planet Nine is likely to be very reminiscent of a typical extrasolar super-Earth,” said Konstantin Batygin, from the Division of Geological and Planetary Sciences at the California Institute of Technology in Pasadena.
Super-earths are planets with a mass greater than planet Earth but substantially less than those of gas giants such as Jupiter and Saturn.
Surveys of extrasolar planets conducted over the last decade have revealed similar-sized planets are common around other stars similar to the sun. Batygin said Planet Nine will be the closest thing that can provide researchers a peek into the properties of what the typical planet in the Milky Way.
Batygin and his colleague Mike Brown, from Caltech, hypothesized the existence of Planet Nine in the outer regions of the solar system beyond Neptune three years ago to explain the behavior of Trans-Neptunian Objects.
TNOs have very unusual orbits around the sun, some of which can be explained by the influence of larger bodies such as planet Neptune. Some of the orbits, however, needed another explanation such as the existence of an unseen object that can disrupt gravity.