Anomalies in the orbits of small bodies in the outer solar system could be due to the presence of two planets more massive than the Earth far beyond the orbit of Pluto, according to researcher Carlos de la Fuente Marcos of Madrid’s Complutense University.
In two separate papers published in Monthly Notices of the Royal Astronomical Society, Marcos and a team of researchers present evidence for the presence of these planets, which may be orbiting four times the distance of Pluto.
He estimated each of these planets to be somewhere between two and fifteen times the Earth’s mass, putting them into the category of “Super Earths,” similarly sized planets found orbiting other stars.
The discovery last year of a remote dwarf planet known as 2012 VP113 with an unusual orbit led Marcos and his team to suspect it is being perturbed by something bigger and further away, as yet undiscovered.
Upon studying the orbits of 13 small objects in the outer solar system, including 2012 VP113, the researchers found all have similar elongated orbits tilted toward the ecliptic, the plane in which Earth and most of the larger planets orbit the Sun.
This, according to Marcos, suggests one or more massive objects is gravitationally perturbing them.
His theory is disputed by some astronomers, who argue that computer models indicate large planets cannot form so far from the Sun.
Ramon Brasser of France’s Cote d’Azur Observatory believes it is Neptune that is perturbing the majority of the small objects, many of which come close to the giant planet.
Marcos disagrees, stating Neptune at most has a weak influence on them.
“If we assume that our models of Solar System formation are correct, the objection is valid. But what if our models are incorrect?” he asks.
He added his team has additional unpublished calculations with stronger evidence for the unknown planets’ existence.
Brasser acknowledges big planets could exist at extreme distances but these would likely not be “Super Earths” but much more massive planets in even more distant orbits.
Any large planets at the distance Marcos suspects the “Super Earths” might be would be dark and therefore undetectable even by the most powerful telescopes on Earth. That is likely to change with the launch of the James Webb Space Telescope and the construction of a new, more powerful ground-based telescopes by the end of the decade.