• Astronomers have discovered 128 new moons orbiting Saturn, bringing its total to 274, nearly double the number of moons orbiting all other planets combined.

• The discovery was made using the Canada France Hawaii Telescope (CFHT) and the “shift and stack” technique, which combines sequential images to detect faint objects.

• All 128 new moons are irregular, potato-shaped objects likely formed from collisions of larger moons or captured asteroids.

• The findings shed light on Saturn’s turbulent past and could help explain the origins of its iconic rings.

• The International Astronomical Union officially recognized the moons on March 11, 2024.

The hunt for Saturn’s hidden moons

Saturn has officially claimed the title of the solar system’s “moon king,” leaving its former rival, Jupiter, in the dust. A team of international astronomers, led by Dr. Edward Ashton of Academia Sinica in Taiwan, has announced the discovery of 128 new moons orbiting Saturn, bringing the ringed planet’s total to an astonishing 274. This discovery, confirmed by the International Astronomical Union on March 11, 2024, solidifies Saturn’s dominance in the moon race, with nearly twice as many moons as all other planets combined.

The findings, made using the Canada France Hawaii Telescope (CFHT), reveal not only the sheer number of Saturn’s moons but also provide a glimpse into the chaotic early days of the solar system. “Sure enough, we found 128 new moons,” said Dr. Ashton. “Based on our projections, I don’t think Jupiter will ever catch up.”

The discovery was the result of a meticulous, multi-year campaign. Between 2019 and 2021, the team used the CFHT to repeatedly monitor the sky around Saturn, employing a technique called “shift and stack.” This method involves taking sequential images of the same patch of sky and combining them to amplify the faint signals of distant objects. The initial observations yielded 62 moons, but the team suspected there were more.

“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,” Dr. Ashton explained. Their persistence paid off, uncovering an additional 128 moons.

Irregular moons and a violent past

All 128 new moons are classified as “irregular moons,” small, potato-shaped objects that were likely captured by Saturn’s gravity during the early days of the solar system. These moons, ranging from a few kilometers in size, are thought to be fragments of larger objects that collided and shattered within the last 100 million years.

“These moons are likely all fragments of a smaller number of originally captured moons that were broken apart by violent collisions, either with other Saturnian moons or with passing comets,” said Dr. Brett Gladman, an astronomer at the University of British Columbia.

The discovery of so many small moons suggests a relatively recent collision within Saturn’s moon system. “Given the high number of small compared to large moons, there was likely a collision somewhere within the Saturn system within the last 100 million years,” Dr. Gladman added. “Otherwise, these moons would have collided with each other and been blown into smithereens.”

Most of the newly discovered moons are clustered in the Mundilfari subgroup, a region of Saturn’s moon system that appears to be the site of this ancient collision. This finding not only highlights the dynamic nature of Saturn’s moon system but also provides clues about the planet’s history and the origins of its iconic rings.

What’s in a name?

For now, the 128 new moons have been assigned strings of numbers and letters, but they will eventually be named after Gallic, Norse, and Canadian Inuit gods, in keeping with the tradition for Saturn’s moons. Most of the new moons fall into the Norse cluster, meaning astronomers will soon be scouring ancient texts for obscure Viking deities.

“Eventually, the criteria may have to be relaxed a bit,” Dr. Ashton joked, acknowledging the challenge of finding enough names for Saturn’s ever-growing moon family.

The discovery of these moons offers more than just bragging rights for Saturn. It provides scientists with a unique opportunity to study the early solar system, a time when planets migrated in unstable orbits and collisions were common. By analyzing the orbits and compositions of these moons, researchers hope to better understand the processes that shaped the solar system and, potentially, the origins of Saturn’s rings.

“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,” said Dr. Ashton.

As Saturn basks in its newfound lunar glory, one question remains: What other secrets does the ringed planet hold? With each new discovery, the solar system reveals itself to be more dynamic and mysterious than we ever imagined. As Dr. Gladman put it, “The universe is full of surprises, and Saturn is no exception.”

For the latest on astronomy, visit Space.news.

Sources include:

TheGuardian.com

Saturn.ubc.ca

MinorPlanetCenter.net