If they exist, these worlds would lie beyond the orbit of Neptune, the farthest known true planet of the Solar System, and even beyond Pluto. Scientists at the Complutense University of Madrid (UCM) were tracking the orbits of a belt of objects known as “extreme trans-Neptunion objects” (Etnos), that lie beyond Neptune’s orbit.
These space rocks are expected to be distributed randomly, with orbits behaving according to certain parameters. But twelve of these bodies behave in a manner that suggests they are influenced by some large, unknown bodies.
Professor Carlos de la Fuente Marcos, the lead scientist from UCM said, “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. 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.”
The debate as to whether there are any large planets beyond Pluto has been going on for decades. “If it is confirmed, our results may be truly revolutionary for astronomy,” said Marcos.
The paper was published in the Monthly Notices of the Royal Astronomical Society Letters last month. If it turns out to be true, this will go against current theories of the formation of the Solar System, according to which, no large planets can exist beyond Neptune. However, a planet was discovered over 100 astronomical units (AU) from the star HL Tauri. One AU is the average distance between the Sun and the Earth, and equals 93 million miles. If a planet is found among the Etnos, it could be as far as 250 AU out.
Further research will be conducted in coming months, based on larger Etno data samples.
