Jupiter has dropped out of the race with Saturn for the title of the Solar System’s most moon-rich celestial body. Recent observations have revealed 128 new satellites around Saturn, bringing the total number of moons around the giant planet to 274. Jupiter has only 95 satellites, or three times less, leaving it no chance of closing the gap.
Saturn and its nearest large moons. Image source: NASA
The first hint that Saturn may have many undiscovered moons came between 2019 and 2021, when 62 new objects were discovered near it. Other small bodies were also spotted at that time, but could not be identified at the time.
«”Knowing that these were probably moons and that there were likely more, we spent three months in 2023 studying the same patches of sky,” said astronomer Edward Ashton of Taiwan’s leading research institute Academia Sinica. “We found 128 new moons. Based on our predictions, I don’t think Jupiter will ever catch up with Saturn in this.”
It should be noted that almost all of Saturn’s new satellites are not classic moons like Earth’s. They are small, irregularly shaped celestial bodies, only a few kilometers across. According to scientists, they were initially a small group of objects captured by Saturn’s gravity early in the Solar System’s existence. Subsequently, a series of collisions turned them into small fragments, which led to the predominance of small rocky bodies that astronomers have recorded.
These catastrophic collisions occurred relatively recently by cosmic standards — only 100 million years ago. This is indicated, for example, by the previously discovered Scandinavian group of Saturn’s satellites. They have already been studied from this point of view: they are also small in size, irregular in shape, and move along elongated orbits, for which they are classified as irregular satellites.
More detailed information about some of the new satellites can be found on the preprint site arXiv, where a paper has already been published.