by Ella Alderson
May 24, 2018

from Medium Website

Spanish version

This isn't Pluto we're talking about.


Planet Nine (ex-Planet Ten or X) is a planet predicted to be about 10 times the mass of our Earth orbiting somewhere in the distant solar system. It was predicted back in '2014' and we have been finding more and more confirmations of it in our solar system ever since.

The main evidence for Planet Nine's existence lies in the strange patterns observed in Kuiper Belt objects out beyond Neptune.


A cluster of these objects have been observed with identically shaped orbits that all travel in the same direction rather than having the random orbits we expect them to.


The orbits are also tilted away from our own under what seems like the influence of a larger source of gravity.


While there is a 1 in 14,000th chance that this could be a coincidence, scientists agree that with the increasing amount of evidence, it is extremely unlikely that this is all random.


The most compelling solution, by far, is the existence of this ever elusive Planet Nine. The Kuiper Belt itself can't be the cause of these anomalies since it would have to be 100 times larger to have that effect on this cluster of objects.

The proposition is that Planet Nine and the KB objects are in a resonance with one another, similar to the orbital resonance that Pluto and Neptune share.


This means that their orbits come into contact with one another and are in sync but the planets and objects themselves never touch.



How the gravity of the theoretical Planet Nine

would affect the orbits of the cluster

of Kuiper Belt objects.

We have also known for many years that the sun is tilted vertically by about six degrees.


With the introduction of this new world, it might come to light that it's actually the planets which are tilted and not the sun.


A collision early on in the formation of our solar system could have caused Planet Nine's orbit to tilt away from the orbits of the other planets, thus resulting in a tilt in our entire system to compensate for the difference.


Computer simulations place the orbital tilt of Planet Nine at 30 degrees, a number which fits perfectly with the current observations we have of our own planets' orbits.

This new world is also estimated to be at a distance 300-900 times greater from the sun than ours and its orbit is so slow that one year on Planet Nine would equal 10.000-20.000 Earth years.

If this still sounds too incredible to believe, consider that our understanding of the universe is not fixed.


Our old geocentric model of the solar system that put Earth at the center was accepted for over 1,000 years before being replaced by the heliocentric model in the 17th century.


And yet the geocentric model was still accurate in predicting cycles of the sky, the seasons, anything we needed at that point in time for life and agriculture.

Neptune was theorized to have existed long before anyone laid eyes on it. Anomalies in the orbit of Uranus led to the speculation that some other body was interfering with the planet's path.


So many astronomers in the 1800's noticed this that by the time Neptune was found in 1846, nobody could decide who had really made the discovery.


Similarly, anomalies in the orbits of Neptune and Uranus led to the discovery of the dwarf planet Pluto in 1930.


The calculations for Neptune's discovery had been so precise that it was found less than one degree from where it was theorized to exist.




So if there is this massive planet in our solar system, what's taking us so long to confirm that it's out there?


Well, we don't know exactly where to look. Unlike with Neptune, we don't have coordinates to where this new planet might be in the huge search area of the distant solar system.


Because it is so far from the sun, it's likely not very visible, either. It's also important where it is during its orbit.


Is it currently close to the sun, or at its furthest point?

Until we do observe it directly, there is a testable hypothesis which says that if the planet is out there, objects on the opposite side of the solar system should have an orbit similar to those of the cluster of Kuiper Belt objects.

"Every time I would do a calculation and I would get the known structure of the solar system right, I would also see the production of these high-inclination objects that lived beyond Neptune.


I think it's becoming increasingly uncomfortable to have a solar system without Planet Nine."

Konstantin Batygin

Astronomer from the CA Institute of Technology

Other theories include that Planet Nine was actually a rogue planet that was captured by the gravity of our own solar system, rather than forming alongside it.

For now we only have about a dozen objects giving us clues as to the existence of the mysterious Planet Nine.


However, it is compelling evidence and it's exciting to think that an entirely new world might be out there for us to discover. Its existence would grant us a more complete picture of our solar system and its infancy.


We would also be able to better predict how often comets reached us and would prompt the question,

"are there even more worlds in our system waiting to be discovered...?"