Are There Co-orbiting Worlds Outside Our Solar System?

Credit: Jeremy Thomas on Unsplash

Trojan worlds, which are co-orbiting planets, have not yet been discovered outside of our solar system. According to recent research, it’s odd considering that we see them all the time in our own backyards.

It is not uncommon to see a huge planet (like Jupiter) in our solar system orbiting the sun at the same distance from the sun as an asteroid. However, tidal forces may modify the orbits of bigger planets, such as an exoplanet. The SETI (Search for Extraterrestrial Intelligence) Institute research argues that giant exoplanets with short-period orbits are driven off of their course by gravitational forces from the neighboring star.

Once expelled, the Trojan is likely to crash with a star or a bigger planet along its path of travel. There are ramifications for our existing 5,000 exoplanet inventory, which is dominated by planets that are near to their parent stars since they are simpler to discover. There is a possibility that Trojans exist, however they are not yet detected using existing methods. Conversely, Trojans may be swiftly deleted from their systems, making them more difficult to detect.

SETI noted in a news release that Earthlings suffer tidal friction due to the Earth’s contact with the moon. During high tide, the Earth’s rotation is slowed and the moon’s distance from the Earth increases. If a star, a gas giant planet, as well as a rocky planet all orbit Lagrange points, or zones of gravitationally stable space between numerous planets, the new research, extends this friction theory to potential exoplanet systems with over two components.

According to the research, the Earth-sized planet’s orbit would become unstable if the tides of the star and the big planet combined. “The tiny planet’s orbit will oscillate from oval to banana-shaped and eventually get out of the shared orbit, smashing with either the star or the massive planet, according to a statement in the press release. The tides may evict Trojans before we can see them, but there may still be some that are in newer systems that may be detected. In addition, a NASA expedition in-flight might provide new information on Trojan behavior. Lucy was launched in October of last year to study Trojan asteroids for the first time.

Susan Kowal
Susan Kowal is a serial entrepreneur, angel investor/advisor, and health enthusiast.