Which planet in the Solar System has the most identifiable moons as of October 2019?
Saturn is the 6th planet from the Sun and the 2nd largest in the Solar System, after Jupiter. It is a gas giant with an average radius about 9 times that of Earth.
Saturn has overtaken Jupiter as the planet with the most moons, according to the International Astronomical Union's Minor Planet Centre on 7 Oct 2019.
The research team consisted of Carnegie Institution for Science's Scott S. Sheppard, David Jewitt of UCLA, and Jan Kleyna of the University of Hawaii. The team discovered a haul of 20 new moons orbiting the ringed planet, bringing its total to 82 which surpassed the 79 of Jupiter.
The moons were discovered using the Subaru telescope on Maunakea, Hawaii.
Each of the newly discovered objects in orbit around Saturn is about 5km (3 miles) in diameter; 17 of them orbit the planet "backwards".This is known as a retrograde direction. The other 3 moons orbit in a prograde direction,the same direction as Saturn rotates.Two of the prograde moons take about 2 years to travel once around the ringed planet.The more-distant retrograde moons and one of the prograde moons each take more than 3 years to complete an orbit.
However, the researchers found that these outer moons orbit Saturn in 3 different clusters called Inuit, Norse and Gallic. “This kind of grouping of outer moons is also seen around Jupiter, indicating violent collisions occurred between moons in the Saturnian system or with outside objects such as passing asteroids or comets,” says Sheppard.