When it comes to the universe, there is a lot that we don’t yet know. Within our little corner of the universe, our solar system, however, most people feel like we know quite a bit, but there are still plenty of mysteries to be discovered.

To start with, there is no precisely defined end to our solar system, so it can be hard to determine what is actually in it and what isn’t. In general, if something is orbiting our sun, it is considered to be within the solar system, but that still leaves a lot of gray area out at the edges.

For large objects like planets, it is generally easier to precisely determine what is within the solar system. The furthest out planet that we know of for sure is Neptune (assuming you don’t follow the old ways and still consider Pluto a planet).

Beyond Neptune, however, there are plenty of dwarf planets, comets, asteroids, and other objects floating about that researchers love looking at. While analyzing the area beyond Neptune, some researchers have noticed some abnormalities. Specifically, some of the things they see are skewed out of position compared to where they are expected to be on the plane of the solar system.

Specifically, trans-Neptunian objects that are in the range of 80 and 200 astronomical units away from the sun show a ‘warp’ of about 15 degrees. An astronomical unit is the distance from the sun to the Earth. The researchers estimate that there is about a 2% chance that this is just a fluke in how the solar system has evolved over the millennia.

The much more likely cause is that there is a planet that has a mass between that of Mercury and Earth, which is orbiting somewhere between 100 and 200 astronomical units away from the sun.

The fact that this area is very far away and that it is a huge area makes it difficult to pinpoint exactly where it is (if it exists). Fortunately, it might be possible to spot it relatively soon thanks to an upcoming decadal survey conducted by the Vera Rubin Observatory.

Researchers who are proposing this planet, which has been dubbed ‘Planet Y’ have published a paper, which is currently available on ArXiv, and has been accepted for publication in the Monthly Notices of the Royal Astronomical Society, commented on this, saying:

“Finally, we note that a hypothetical Planet Y as described in this work would likely be detectable by the upcoming Legacy Survey of Space and Time (LSST) on the Vera C. Rubin Observatory if it is currently located within the survey footprint. If such a body exists but is not discoverable by LSST due to its on-sky location (i.e., high ecliptic latitude), LSST will nevertheless elucidate the details of the Kuiper belt mean plane warp induced by the planet.”

Depending on what is found (if anything), this may have to start a new debate as to whether this Planet Y is to be considered one of the official planets of our solar system, bringing the total back up to 9, or if it will be classified in some other way.

If you thought that was interesting, you might like to read about why we should be worried about the leak in the bottom of the ocean.