By Sofie Bates
Saturn now reigns as the solar system’s “moon king,” thanks to 20 newfound moons. That brings the ringed planet’s total known satellites to 82, knocking Jupiter — with 79 moons (SN: 7/17/18) — off the throne, the International Astronomical Union’s Minor Planet Center announced October 7.
And it’s not just a phase. Saturn is likely to keep its title, says Scott Sheppard, an astronomer at the Carnegie Institution for Science in Washington, D.C. He estimates that Saturn has about 100 moons — but the remaining ones are so small, under 1 kilometer across, that they’re hard to identify.
As it is, it took Sheppard and his colleagues years to confirm that some of the specks captured in images taken from 2004 to 2007 by the Subaru Telescope in Hawaii were, in fact, moons orbiting Saturn. By comparing the objects’ locations over time, the team found that three of the newfound moons are prograde, orbiting in the same direction that Saturn rotates, while 17 are retrograde, traveling in the opposite direction. Each is between 2 and 5 kilometers wide.
Continue reading by clicking the name of the source below.