Since downgrading Pluto’s status to a dwarf planet, scientists have attempted to find a replacement ninth planet in our solar system. Now, a team of astronomers believes that there are 10 or 11 more planets hiding in our solar system.

In January, astronomers from the California Institute of Technology (Caltech) claimed that Planet Nine exists after analyzing that the six extreme trans-Neptunian objects (ETNOs) in the Kuiper Belt moved together by the gravity of a large object. However, scientists from Spain and the Institute of Astronomy of the University of Cambridge say that these ETNOs are not as stable as previously thought, which can only be explained by the influence of more planets at the outer edges of our solar system.

“With the orbit indicated by the Caltech astronomers for Planet Nine, our calculations show that the six ETNOs (extreme trans-Neptunian objects), which they consider to be the Rosetta Stone in the solution to this mystery, would move in lengthy, unstable orbits,” adds Spanish freelance astronomer Carlos de la Fuente Marcos. Carlos worked with his brother, Raúl de la Fuente Marcos, also a freelance astronomer.


The orbits of the six ETNOs which is thought to be influenced by the presence of Planet Nine. Credit: Caltech/R. Hurt (IPAC)

The study published on April 25 in the journal Monthly Notices of the Royal Astronomical Society involved using computer simulations. The six ETNOs are Sedna, 2004 VN112, 2012 VP113, 2007 TG422, 2013 RF98 and 2010 GB174.

“If the ETNOs are transient, they are being continuously ejected and must have a stable source located beyond 1,000 astronomical units (in the Oort cloud) where they come from”, says Carlos. “But if they are stable in the long term, then there could be many in similar orbits although we have not observed them yet”.

These findings will now help the research team improve the knowledge about Planet Nine. Further analysis of these ETNOs can reveal the exact location of the mysterious ninth planet.

Planet Nine is believed to be a giant planet that has ten times more mass than Earth. It moves in a very long orbit, which takes it between 10,000 and 20,000 years to complete one revolution around the sun.