Scientists have discovered 20 new satellites for Saturn, bringing the total number of this planet’s natural satellites to 82, 3 more than Jupiter.
The 20 new satellites are all very small, with a diameter of only about 5 km. 17 of them have retrograde orbits, meaning they move around Saturn in the opposite direction to the planet’s rotation. These 17 satellites take more than 3 years to complete a circle around Saturn, and the farthest satellite among them is also Saturn’s farthest satellite, the research team said.
One of the 3 satellites in transit (prograde, opposite to retrograde) was found to complete one orbit around Saturn in 3 years, while the other 2 satellites only take about 2 years.
These two images were taken 1 hour apart using the Subaru telescope. The stars and galaxies in the background don’t move, but Saturn’s new moons do. Source: Scott Sheppard
The 17 retrograde moons appear to belong to the “Nordic group” of Saturn’s moons because their orbital parameters are similar. The two innermost prograde satellites are similar to the “Inuit group” and the outermost prograde satellite of the newly discovered number probably belongs to the “Gallic group”, but this has not yet been confirmed.
Each of the three groups above is likely evidence of a long-ago collision. This collision destroyed a large satellite that was moving in this region.
“Such groups of outer satellites also appear on Jupiter, indicating that violent collisions have occurred between moons located in Saturn or the Saturn system. [va chạm] with external celestial bodies such as comets or meteorites,” Scott Sheppard, working at the Carnegie Institute of Science in Washington DC, announced yesterday (October 7).
Simulation of the orbits of 20 newly discovered Saturn satellites. Source: Carnegie Science
Sheppard is the leader of the research team. He and colleagues David Jewitt (University of California, Los Angeles) and Jan Kleyna (University of Hawaii) discovered new Saturn satellites using the Subaru Telescope in Hawaii.
“Using some of the world’s largest telescopes, we are taking inventory of tiny moons orbiting giant planets. They play an extremely important role in helping us determine how the planets in the solar system form and evolve. – added Scott Sheppard.
For example, the existence of new moons indicates that the tectonic collisions that created them occurred shortly after Saturn formed. A disk of gas and dust surrounded the gas giant when it formed. If the tiny moons passed through this mass of matter while orbiting Saturn, friction would stop their speed and force them to spiral toward the parent planet.
American astronomer Scott Sheppard, who discovered many new satellites, comets and asteroids.
Last year, Sheppard discovered a dozen moons of Jupiter. Immediately afterwards, the Carnegie Institute held a competition to name these five new satellites.
“I was so excited by the overwhelming community participation in the Jupiter naming contest that we decided to hold another contest to name these new moons of Saturn. This time, the satellites must be named after Nordic, Inuit or Gallic mythological giants. – said Sheppard.
The 20 newly discovered satellites will be named by the organization. If you are interested, please send a proposal by tweeting @SaturnLunacy by December 6. Don’t forget to add the reason for the offer and the hashtag #NameSaturnsMoons.
Visit Carnegie Science’s Saturn Naming Contest for more details.