Interesting research was published last month from the University of Idaho. Doctoral student Rob Chancia, and Physics Assistant Professor Matt Hedman, have been investigating significant patterns Chancia found in photographs taken by the Voyager 2 back in 1986.
The Voyager 2 is a probe that was launched by Nasa in 1977. The probe is still exploring the outreaches of the Solar System today, 39 years from launch, communicating back to us through the Deep Space Network. Before reaching the outskirts of our Solar System, the Voyager 2 spent some time in the Neptunian, Uranian, Saturnian and Jovian systems. Some photographs taken during it’s stint in the Uranian system in 1986 caught the attention of Chancia. He noticed patterns in the rings showing different wavelengths, demonstrating that there is a disturbance breaking up the symmetry of the radial wavelengths. These disturbances could be wakes from small moonlets orbiting Uranus
Why have these moons never been noticed before?
Chancia and Hedman have used the structure of the patterns in the rings to work out that the moons must be as small as 2-7km in radius and the images taken by the Voyager 2 in 1986 simply were not sensitive enough to pick these up. Furthermore the Uranian moons are covered in dark material which make them very difficult to spot!
What would the existence of these moons mean for our knowledge of the planets?
The discovery of the moonlets would help explain why the rings of Uranus are so much narrower than Saturn’s. The moonlets could be acting as “shepherd” moons, a term for a moon whose placement and effect of gravity help to maintain a ring’s sharply defined edge.
What’s the next step?
Other researchers will have to use telescope or spacecraft images to find out if these moonlets are really out there!
Watch this space…