Don’t get your hopes up – scientists aren’t making Pluto a planet again just yet. But the number of planets that exist in our solar system could be bumped up by two. Last fall researchers published a study on the mysterious Planet Nine, which could explain the unusual tilt of the sun. Now University of Arizona (UA) scientists think they may have found evidence for yet another planetary mass object – and it could be closer than Planet Nine.

Solar system, planet, planets, Planet Nine, Planet 10, space, outer space, science, University of Arizona, mass, planetary mass object, planetary body, orbits, orbital planes, Kuiper Belt, Kuiper Belt objects, KBOs

Planet Nine – which scientists think might be 10 times Earth’s mass – could be lurking out past Pluto’s orbit. But Planet Nine might not be all we’ve missed in our solar system. Kat Volk and Renu Malhotra of the Lunar and Planetary Laboratory at UA think they’ve found an unknown planet that’s between the mass of Earth and Mars. What gave this potential planet away was the fact it could be controlling the orbital planes of Kuiper Belt objects (KBOs) – a group of space rocks.

Related: New research suggests an unseen 9th planet may be tilting the solar system

Solar system, planet, planets, Planet Nine, Planet 10, space, outer space, science, University of Arizona, mass, planetary mass object, planetary body, orbits, orbital planes, Kuiper Belt, Kuiper Belt objects, KBOs

In the Kuiper Belt, the furthest away of the KBOs don’t orbit the sun with orbital tilts scientists would expect. Instead, they’re tilted away by around eight degrees, suggesting a mysterious something might be warping their orbital planes. Volk, lead author on a study slated for publication in the Astronomical Journal, said in a statement, “The most likely explanation for our results is that there is some unseen mass. According to our calculations, something as massive as Mars would be needed to cause the warp that we measured.”

Why haven’t we yet stumbled across this potentially rather large planet? Volk and Malhotra say we haven’t searched the whole sky for distant objects in the solar system – Planet 10 may have been hiding among the densely packed galactic plane. We might catch a glimpse of Planet 10 when the construction of the Large Synoptic Survey Telescope – an instrument operated by a consortium including UA – is completed, possibly in 2020.

Via Futurism and the University of Arizona

Images via Heather Roper/LPL