A team of astronomers from Taiwan, Canada, the United States, and France has discovered 128 new moons orbiting Saturn, bringing the planet’s total known moons to 274. This latest discovery cements Saturn’s position as the planet with the most moons in the solar system—nearly twice as many as all other planets combined.
Astronomers Confirm Groundbreaking Discovery
Dr. Edward Ashton, a researcher at Academia Sinica’s Institute of Astronomy and Astrophysics in Taiwan, confirmed the findings in an interview with The Guardian, stating, “Yes, we have indeed discovered 128 moons.”
He added, “Based on our predictions, Jupiter will never be able to surpass Saturn in terms of moon count.”
Previously, the same research team had identified 62 moons around Saturn using the Canada-France-Hawaii Telescope (CFHT). As of February 5, 2024, Jupiter had 95 confirmed moons.
Newly Identified Moons Officially Recognized
The International Astronomical Union (IAU) has officially recognized these new moons and assigned them identification codes consisting of numbers and letters.
To detect the moons, astronomers used a technique called “shift and stack”, which involves capturing multiple images along the projected motion of a moon and combining them to create a brighter, more visible image.
Characteristics of the Newly Discovered Moons
All of the 128 newly identified moons are classified as “irregular moons.” These are small, potato-shaped objects just a few kilometers in diameter, significantly smaller than Earth’s moon, which has a diameter of 3,474 km (2,159 miles).
These moons orbit Saturn at distances ranging from 10.5 million km (6.5 million miles) to 29 million km (18 million miles)—much farther than Saturn’s rings and major moons.
Ancient Fragments of Larger Moons
Astronomers believe these newly discovered moons are remnants of ancient celestial bodies that were captured by Saturn’s gravity in the early solar system. Over time, collisions with other moons or comets likely shattered them into smaller pieces, according to Brett Gladman, an astronomer at the University of British Columbia in Canada.
The research team has grouped these moons into families based on their shared origins. One such group, named Mundilfari, consists of 47 newly discovered moons and is believed to have fragmented at least 100 million years ago.
Redefining What Counts as a Moon
As telescope technology improves, astronomers continue to detect more orbiting objects, sparking debates over what should be classified as a moon versus just a large space rock.
“There is no clear definition of what qualifies as a moon, and I believe we need one,” Ashton told The Guardian.
For now, the IAU classifies any object with a stable orbit around a planet as a moon, regardless of its size.
Saturn Widens Its Lead Over Jupiter
For years, Jupiter and Saturn have competed for the title of the planet with the most moons. However, this latest discovery has secured Saturn’s dominance, making it highly unlikely that Jupiter will ever reclaim the top spot.