Back in school, we learned the mnemonic "My Very Excellent Mother Just Served Us Nine Pizzas" to remember all the planets in our solar system.
That pizza might have toppings.
According to el Servicio de Información y Noticias Científicas (SINC) - Information and Scientific News Service, in English - there might be two planets hiding beyond Pluto. The gravitational pull of the two out-of-sight planets could be causing mysterious movement around Neptune, according to researchers at the University of Madrid and the University of Cambridge.
The orbits of the extreme trans-Neptunian objects (ETNO) should "fulfill a series of characteristics: have a semimajor axis with a value close to 150 AU (astronomical units, where 1 AU is the distance between the Earth and the Sun), an inclination of almost 0 degrees, and an argument or angle of perihelion (closest point of the orbit to our Sun) also close to 0 degrees or 180 degrees," according to SINC.
But "the values of the semimajor axis are very disperse (between 150 AU and 525 AU), the average inclination of their orbit is around 20 degrees, and argument of perihelion -31 degrees, without appearing in any case close to 180 degrees."
In other words, they aren't doing what they are supposed to be doing.
"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," said Carlos de la Fuente Marcos, a scientist at the University of Cambridge and co-author of the study, according to SINC.
"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," he added.
