Astronomers have discovered 128 never-before-seen moons orbiting Saturn — giving it almost twice as many moons as all the other planets in the solar system combined.
The findings have further bolstered Saturn’s status as our solar system’s “moon king.” With an updated total of 274 known natural satellites orbiting the gas giant, it is leagues ahead of its main competitor Jupiter, which has just 95 confirmed moons.
This week, the International Astronomical Union officially recognized the team’s discovery. The researchers published their findings March 10 in the journal arXiv, so they have not yet been peer-reviewed.
“Our carefully planned multi-year campaign has yielded a bonanza of new moons that tell us about the evolution of Saturn’s irregular natural satellite population,” study lead author Edward Ashton, an astronomer at Institute for Astronomy and Astrophysics at Academia Sinica, Taiwan, said in a statement.
The newfound moons are situated within the Norse group of Saturn’s moons — a group of moons that orbit in retrograde (travelling in the opposite direction to the planet’s rotation) along elliptical paths outside Saturn’s rings. The 128 newly discovered objects are considered “irregular” moons, meaning they’re only a mile or two in size and far from spherical.
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Their diminutive sizes and location means these moons are likely fragments of larger moons that were smashed apart by a cataclysmic collision — probably with Saturn’s other moons or a passing comet. This collision could have occurred as recently as 100 million years ago, the astronomers said in the study.
The discovery was made using the Canada France Hawaii Telescope (CFHT), which combed the sky around Saturn between 2019 to 2021 and discovered an initial 62 additional moons in its orbit. The team also found faint signals of an even larger number of orbiting bodies but were unable to confirm them at the time.
“With the knowledge that these were probably moons, and that there were likely even more waiting to be discovered, we revisited the same sky fields for three consecutive months in 2023,” Ashton said. “Sure enough, we found 128 new moons. Based on our projections, I don’t think Jupiter will ever catch up.”
The researchers say they are now finished moon-spotting for the foreseeable future, at least until telescopes capable of spotting even fainter signatures are developed.
“With current technology I don’t think we can do much better than what has already been done for moons around Saturn, Uranus and Neptune,” Ashton said.