A recently flagged and yet-to-be peer-reviewed paper highlights that the planet Uranus is in a stable orbital resonance with a minor planet, a Centaur named 2015 OU₁₉₄. They have a 3:4 orbital resonance, for every 4 orbits that Uranus completes around the Sun, 2015 OU₁₉₄ completes 3. This locks the two in a coordinated, celestial orbital dance, keeping them from drifting apart or colliding. Scientists suggest that it has lasted for 100o years or even a million years and is likely to continue for another half a million years.
Why does it matter?
In the vast space between Uranus and Neptune, 2015 OU₁₉₄ follows a nearly circular orbit. Centaurs are rocky and icy objects that are found between Jupiter and Neptune. They usually exhibit chaotic, shifting orbits. A stable, long-term dance like this is extraordinary. This also hints at hidden gravitational relationships between the bodies in the outer solar system.
Researchers led by Daniel Bamberger from the Northolt Branch Observatories in Germany scanned through the archival data of 2017 and 2018 from the observation of 2015 OU₁₉₄. and extended the data points from 1 to 3.5 years, this longer observation provided them true nature of the orbital resonance. They published a research paper titled ‘A minor planet in an outer resonance with Uranus’, uncovering the extraordinary findings.
Moreover, other centaurs like 2013 RG₉₈ have also been revealed, which had been engaged in an orbital dance of 3:4 resonance with Uranus. Other candidates like 2014 NX₆₅ also show a strong gravitational influence from Neptune.
These also imply that a similar relationship may also be valid for more objects in the outer Solar System, and these partnerships might be fundamental to the understanding of that region.