Last week the team led by astronomer Scott S. Sheppard of the Carnegie Institute of Science discovered 20 new satellites in orbit around the planet Saturn. With this discovery the planet now has 82 known moons.
These satellites have an average of 5km in diameter. 17 of them follow retrograde orbits, that is, they rotate in the opposite direction to the planet's rotation. The other 3 follow straight orbits. The "years" of these moons (the time it takes to turn around Saturn) is 2 to 3 Earth years.
Sheppard explained to the media that Saturn's satellites appear to be grouped into 3 types of orbits, according to their angle of inclination, the interiors at 36 °, the exteriors at 46 °, and the retrograde ones. Of the satellites discovered, 2 fit in the outdoor classification, 17 in the retrograde classification, and 1 is ambiguous classification, because despite having an inclination of 36 ° it has an outer orbit.
Sheppard explains that retrograde orbit satellites could have been the rest of a clash between larger bodies, and that the ambiguous object could have been an inland satellite dragged out by time, or have nothing to do with inner satellites at all and belong to another group.
Here is the tweet shared directly from the Carnegie Institute and an explanatory video: