Astronomers have spent decades debating whether some dark trans-Plutonian planet remains to be discovered within the solar system. According to the calculations of scientists at the Complutense University of Madrid (UCM, Spain) and the University of Cambridge (United Kingdom) not only one, but at least two planets must exist to explain the orbital behaviour of extreme trans-Neptunian objects.
“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,” adds the astrophysicist Carlos de la Fuente Marcos, co-author of the study.
But there are still two problems
Despite their surprising results, the authors recognise that their data comes up against two problems. On the one hand, their proposal goes against the predictions of current models on the formation of the solar system, which state that there are no other 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, which is younger than the Sun and more massive, suggests that planets can form several hundred astronomical units away from the centre of the system.
On the other hand, the team recognises that the analysis is based on a sample with few objects (specifically 13), but they point out that in the coming months more results are going to be published, making the sample larger. “If it is confirmed, our results may be truly revolutionary for astronomy,” says de la Fuente Marcos.
Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began in the mid-19th century and culminated at the start of the 20th with Percival Lowell‘s quest for Planet X. Lowell proposed the Planet X hypothesis to explain apparent discrepancies in the orbits of the giant planets, particularly Uranus and Neptune.
Planet X has become deeply associated with Nibiru, a planet from the works of ancient astronaut proponent Zecharia Sitchin, particularly his book The 12th Planet. According to Sitchin’s interpretation of Babylonian religious texts a giant planet (called Nibiru or Marduk) passes by Earth every 3,600 years and allows its sentient inhabitants to interact with humanity. These beings, which Sitchin identified with the Annunaki of Sumerian myth, would become humanity’s first gods.