Saturn now has the most moons = 82

20 new moons of Saturn have been discovered by the Carnegie Institution for Science - using the 8.2 metre Subaru telescope on Mauna Kea, Hawaii. The picture below shows the massive Subaru telescope, looking past the side of Keck 1 which we had just visited. The telescopes on the top of Mauna Kea have continued to make remarkable discoveries over many decades. The latest discovery of 20 Saturn moons means that Saturn now tops the list of planets with the most moons. The champion was Jupiter with 79 moons, but Saturn has overtaken Jupiter with a total of 82 moons.

The new moons were found in a similar way to Pluto - where an image of the region was taken and then one hour later another image of the same field of view was produced. The background stars stayed still - but one by one a moon was found to have moved across the star field as it travels much closer to Earth.

The 20 moons are all small - maximum 5km across. 17 move in retrograde motion and 3 in the normal anticlockwise motion. The moons are a long way from Saturn and take between 2 to 3 years to orbit the planet. One moon is the furthest of all of Saturn’s moons. All the moons have been confirmed by the Minor Planet Centre that registers all new discoveries once they have been verified.

The furthest moon is possibly one of the Gallic moons that orbit at an inclination of 36 degrees. The other two moons that also orbit in an anticlockwise motion are inclined at 46 degrees and are part of the Inuit group of moons. All the retrograde moons have a similar inclination to some of the other Saturn moons of the Norse group. One theory is that the small fragments are the result of a larger moon having been smashed to pieces by a large impact.

Further details can be gained from the discovery telescope (which includes the actual photographs showing one of the moon’s motion that allowed its discovery):-

https://subarutelescope.org/Pressrelease/2019/10/07/index.html