Scientists have been investigating extreme trans-Neptunian objects and have come to the conclusion that two additional planets could be lurking in our Solar System. In fact, astronomers believe that there may be more planets that have yet been discovered in the “inner Oort cloud”, an area that hasn’t been thoroughly studied.
A team of scientists from the UK and Spain claims that our solar system contains at least two additional planets located beyond the orbits of Neptune and Pluto. This hypothesis is necessary, the scientists claim, in order to explain the orbital patterns of celestial objects located farther away (called “extreme trans-Neptunian objects).
According to currently accepted theories, the orbits of extreme trans-Neptunian objects are expected to be distributed evenly. Furthermore, all these orbits are subject to particular characteristics: the orbit’s semi-major axis should have an axis of 150 Astronomical Units, a 0 degree inclination and an argument of perihelion (which represents the point of the orbit where the ETNO is closest to the Sun) close to 0 or 180 degrees. Despite this theory, however, astronomers have noticed different characteristics for some of the ETNO’s they have been studying.
On the one hand, the semi-major axis values presented different values (ranging from 150 to 525 Astronomical Units) while the orbit’s average inclination measured at 20 degrees. Even the argument of Perihelion was different, at approximately 31 degrees. Because of these findings, astronomers had to revisit their initial hypothesis.
The team of researchers soon realized that other large objects must exist so that invisible forces could significantly alter the way that the ETNO’s orbital elements are distributed. After consideration, the most likely explanation that scientists proposed was that unknown planets had to be in play.
Carlos de la Fuente Marcos, a study co-author working at the UCM (Complutense University of Madrid), explained that astronomers are still working with limited data, but that calculations strongly suggest:
“that there are at least two planets, and probably more, within the confines of our solar system,”
Researchers studied the “Kozai mechanism” in an attempt to prove their theory. This mechanism relates to the significant gravitational perturbation exerted by large bodies on the orbits of other, smaller, celestial bodies. Astronomers first studied the influence of Jupiter on comet 96P/Machholz1 and its orbit. The team of researchers believes that this influence could have an essential role in explaining the mind-boggling “clustering of orbits around argument of perihelion close to 0°” which is evident in ETNO’s.
The team then shifted its focus on a dwarf planet called VP113. This planet was discovered two years ago on the Oort cloud. Astronomers believe that VP113 is another planet whose orbit is influenced by an unknown celestial body, perhaps an “icy super Earth”.
Scientists explain that VP113 has been identified as the dwarf planet with the most distant perihelion of our solar system. As VP113 shares these characteristics with the majority of identified ETNO’s, astronomers believe that this could be interpreted as “evidence for the existence of a super-Earth at 250 au.”
The team of researchers explained that, in such a scenario, an undiscovered planet, many times larger than Earth, would be shepherding the population of stable asteroids. This yet undiscovered planet, as the Kozai mechanism states, would be responsible for maintaining the asteroids’ argument of perihelion at approximately o degrees.
Another observation in support of the researchers’ claim was the discovery of a planet-forming disk located near HL Tauri. HL Tauri is a massive and significantly younger star than our Solar System’s star. By making this discovery, the team of scientists raised the possibility that the formation of planets might be likely at distances of hundreds astronomical units away from the Solar System’s star. This disk is approximately 100 Astronomical Units away from its star.
These observations were possible after the team of scientists studied the behavior of thirteen different celestial objects. Consequently, the need of additional observations, especially in remote regions of our Solar System, is undeniable.
However interesting such a theory might seem, it contradicts the currently accepted models explaining the formation of our Solar System. These models state that no additional planets exist moving beyond Neptune’s orbit.
Image Source: whillyard
Image Source: Brian Koberlein
Image Source: FY Solar System
