Scientists believe that there might be a ninth planet in our solar system, as they have detected a Mars-sized object lurking behind the Kuiper belt. Officially, there are eight planets in the solar system, but scientists at the University of Arizona’s Lunar and Planetary Laboratory (LPL), are convinced there is an unseen mass hiding within the Kuiper belt.

The Kuiper Belt is a region at the edge of the solar system filled with countless icy bodies, such as asteroids, comets, and dwarf planets.

Artistic rendition of Planet 10. Image Credit: Heather Roper/Lunar and Planetary Laboratory
Artistic rendition of Planet 10. Image Credit: Heather Roper/Lunar and Planetary Laboratory

A separate team of scientists said in January 2015 that a planet as massive as Neptune might lie beyond Pluto. They calculated that this “Planet 9” is over 25 times farther from the Sun than Pluto is. So, now that there’s a new group of researchers claiming there’s another planet beyond Pluto, people are referring to such planet as “Planet 10.”

‘Planet 10’ may be lurking beyond the Kuiper belt

The researchers at the LPL believe that Planet 10 is on the outer rim of the solar system. They determined this by studying the orbital tilts of over 600 icy space-rock Kuiper Belt objects (KBOs), and once they did this, they found that their orbital tilts are slightly different than what they would expect.

The University of Arizona published a press release this week, in which they noted that this could only mean that a mysterious mass may be altering the average orbital plane of the outer solar system.

“According to our calculations, something as massive as Mars could be needed to cause the warp that we measured,” said the study’s co-author, Kat Volk, according to The Inquisitr.

It is possible that another planet exists in the outer solar system, but it may be hard to see it due to its location and coldness. New breakthroughs in science are allowing scientists to find celestial bodies and planets with state-of-the-art telescopes, such as the James Webb Space Telescope. However, there is another way to search for planets: by the gravitational tug they exert on other bodies.

Image Credit:
Image Credit:

In fact, gravitational tug revealed the existence of Neptune. After Uranus’ discovery centuries ago, scientists noted its motion did not agree with the predictions of Newtonian gravity. However, the pull of an unknown planet could explain the deflection of its orbit. In the mid-1800s, Urbain Le Verrier and John Couch Adams calculated the position that matched that description independently. Moreover, soon after Le Verrier’s predictions, Johanne Galle found Neptune using those predictions.

The method had also failed in the past, like when strange motions of Mercury caused scientists to predict a planet that doesn’t exist. They saw that general relativity caused Mercury’s odd orbital trajectory.

Based on data from gravitational tug, Planet 10 might be as large as Mars

Spotting a gravitational tug from a distant world is difficult. The distances are greater and the gravitational influences are weaker. Nevertheless, there are hundreds of known objects beyond Neptune called Trans-Neptunian Objects (TNOs), and serve as tools to look for other planets. The Planet 9 theory talked about the existence of a super-Earth planet in the outer solar system, and this seemed likely because the orbits of the most distant TNOs are clustered together. However, the most recent survey of outer worlds demonstrated that detection bias caused the clustering and scientists shut down the Planet 9 hypothesis.

Although the latest survey of TNOs ruled out the existence of a super-Earth, it leaves open the possibility of a smaller planet, Planet 10. All the planets in our solar system have orbits that are all in the same plane, called the invariable plane. Since the solar system is gravitationally isolated, scientists would expect the orbits of TNOs to have similar orientations. Orbits would vary a little, but the normal orientation should be near the invariable plane.

However, the latest survey found that the orbital orientations of distant TNOs show a tilt of around 8 degrees from the invariable plane. It would not be unusual that a single orbit would have this tilt, but it is unusual for so many orbits to have it. This type of shift can happen due to a gravitational tug from a larger body, and based on the data, that planet would be at least the size of Mars.

Researchers hope the LLST telescope will help them find the planet

When the researchers at the LPL were asked if it’s possible that the variances in orbital tilts of KBOs could have been caused by the so-called Planet 9, they said no, explaining that it’s far too distant to do that.

James Web Space Telescope's massive 6.5-meter primary mirror. Image Credit: NASA/Chris Gunn
James Web Space Telescope’s massive 6.5-meter primary mirror. Image Credit: NASA/Chris Gunn

“That is too far away to influence these KBOs,” said Volk, according to The Inquisitr. “It certainly has to be much closer than 100 AU to substantially affect the KBOs in that range.”

At the moment, researchers do not have the technology to determine if there’s a Planet 10 within the Kuiper Belt. However, they are working on it, as scientists hope that the highly-advanced Large Synoptic Survey Telescope (LSST), which will be fully operational in 2020, will help them discover these planet-size objects.

Source: The Inquisitr