Planet 9 could be something entirely different.

What if there is no “Planet Nine” wreaking havoc in the outer solar system? A research team from Jülich has a different theory.

Jülich – One might think that all is well in the solar system. Eight planets orbit the sun in orderly orbits, and that’s it. But far from it: There are much more than just eight planets in our solar system, and that also includes countless other objects such as asteroids, comets and dwarf planets.

Especially when it comes to objects moving in the outer solar system (so-called trans-Neptunian objects), things aren't as orderly as one might think. There are certainly some orbits so strange and fascinating that researchers have been studying them for years.

Is There a Planet Nine in the Outer Solar System? A New Study Has a Different Theory

Some of these peculiar features seem to point to a ninth planet in our solar system. In fact, some of the strange orbits have been calculated to indicate the gravitational influence of a planet about five times the mass of Earth and located far from the sun. The problem: That far from the sun is dark—and it’s very difficult to detect an unknown planet whose orbit you don’t know. That’s why “Planet 9” has yet to be discovered, even though the search has been going on for several years.

An alien star may have passed through the solar system and caused destruction.

Two new studies (published in Astronomy Nature and Astrophysical Journal Letters) now suggests that there may also be another explanation for the sometimes eccentric orbits of celestial bodies in the outer Solar System: the flyby of a strange star. It could have flown very close to our Solar System billions of years ago, potentially putting thousands of smaller celestial bodies in the outer Solar System into highly inclined orbits around the Sun. A research team from Jülich Research Center and Leiden University investigated this scenario.

The three-person research team ran more than 3,000 computer simulations. “The best match for today’s outer solar system that we found in our simulations is a star that was slightly lighter than our Sun — about 0.8 solar masses,” co-author Amith Govind explains in a paper. Note“This star flew past our sun at a distance of about 16.5 billion kilometers.”

The model also answers another unexplained phenomenon in the solar system.

This explanation could also explain other phenomena. During the simulations, some trans-Neptunian objects were thrown into the solar system – the region where the giant planets Jupiter, Saturn, Uranus and Neptune lie. “It is possible that some of these objects were captured by the giant planets as moons,” says co-author Simon Porteges Zwart. “This would explain why the outer planets of our solar system have two different types of moons.”

Co-author Susan Pfalzner is pleased with the result: “The beauty of this model is its simplicity. It answers many open questions about our solar system for one reason alone. It’s possible that stars in the Milky Way have experienced something similar.” (unpaid invoice)