Uranus continues to surprise us even after 30 years of Voyager 2 mission and in a latest finding it has been suggested that the ringed planet could be hiding two undiscovered tiny moons.
Researchers at University of Idaho and colleagues have suggested based on patterns they observe in the rings of Uranus that there is a strong possibility of existence of two tiny moons orbiting Uranus – one in its alpha ring and the other in its beta ring. Researchers say that they reexamined the data from Voyager 2 spacecraft and what they found was surprising. They found that amount of ring material on the edge of the alpha ring and beta ring varied periodically. They also observed that the wavelength of these patterns was different from different places and this means that there is something present in these rings that is breaking the symmetry.
Using data from Cassini regarding Saturn’s rings, scientists have learnt new things about how rings around planets behave and using this understand, researchers reexamined the Uranus data. What they looked at specifically was radio occultations and stellar occultations. Radio Occultations were made when Voyager 2 sent radio waves through the rings to be detected back on Earth while the stellar occultations were made when the spacecraft measured the light of background stars shining through the rings thereby revealing how much material they contain. Researchers say that the patterns in Uranus’ rings were similar to moon-related structures in Saturn’s rings called moonlet wakes.
According to hypothesis, these two moonlets could be anywhere between 2 to 7 kilometers in radius. These moons are hard to spot because they are made of a mix of frozen water and unknown other materials that give them low albedo, or brightness.
While the team hasn’t been able to make direct observations of the two proposed moons yet, they say that the idea is the size of the moons needed to make these features is quite small, and they could have easily been missed. These findings could help explain some characteristics of Uranus’ rings, which are strangely narrow compared to most of Saturn’s. The moonlets, if they exist, may be acting as “shepherd” moons, helping to keep the rings from spreading out. Two of Uranus’ 27 known moons, Ophelia and Cordelia, act as shepherds to Uranus’ epsilon ring.
Confirming whether or not the moonlets actually exist using telescope or spacecraft images will be left to other researchers say. They will continue examining patterns and structures in Uranus’ rings, helping uncover more of the planet’s many secrets.