A new study has found that at least two unknown dwarf planets may be hiding at the edges of our solar system, beyond Pluto. According to calculations by scientists at the Complutense University of Madrid and the University of Cambridge, not one, but at least two dwarf planets must exist beyond Pluto in order to explain the orbital behavior of extreme trans-Neptunian objects.
As of last year, there were 1,352 trans-Neptunian objects on the Minor Planet Center's list. Of these, 200 have their orbits determined well-enough that they have been designated as permanent minor planets. Scientists now believe that there must be planets beyond Pluto to explain the orbit of many of these objects.
The most accepted current theory about these objects is that the orbits should be distributed randomly, and their paths must fulfill a series of characteristics, including a semi-major axis with a value close to 150 times the distance between Earth and the sun, an inclination of 0 degrees, and the closest point of their orbit to the Sun must be close to 0 or 180 degrees.
However, at least a dozen of the orbits of these objects do not even come close to this set of characteristics.
"This excess of objects with unexpected orbital parameters makes us believe that some invisible forces are altering the distribution of the orbital elements of the ETNO and we consider that the most probable explanation is that other unknown planets exist beyond Neptune and Pluto," explains Carlos de la Fuente Marcos, scientist at the UCM and co-author of the study.
Scientists believe the gravitational influence of at least two planets beyond Pluto are the reason why many of these objects don't meat the criteria.
"The exact number is uncertain, given that the data that we have is limited, but our calculations suggest that there are at least two planets, and probably more, within the confines of our solar system," de la Fuente Marcos says.
Researchers acknowledge that the sample is small, but future papers will make the sample much larger. "If it is confirmed, our results may be truly revolutionary for astronomy."
Their data and proposal directly contradicts most of the current models of predication for how the solar system was formed, which state that there are no planets moving in circular orbits beyond Neptune. However, the recent discovery by the ALMA radio telescope of a planet-forming disk more than 100 astronomical units from the star HL Tauri suggests that planets can, in fact form several hundred astronomical units away from the center of a system.