Saturn reclaims 'moon king' title

With 62 newly discovered moons, Saturn surpasses Jupiter to become the planet with the most moons in the Solar System.

Hubble Space Telescope image of Saturn in June 2018. Image: NASA/ESA/A. Simon (GSFC)/OPAL Team/J. DePasquale (STScI) — Hubble Space Telescope image of Saturn in June 2018. Image: *NASA/ESA/A. Simon (GSFC)/OPAL Team/J. DePasquale (STScI)*

Before the new discovery, Saturn had 83 moons recognized by the International Astronomical Union (IAU). Now, that number has increased to 145, Space reported on May 12. This also marks an important milestone for Saturn, making the planet the first known celestial body in the universe to have more than 100 moons orbiting it.

Edward Ashton, a postdoctoral fellow at the Institute of Astronomy and Astrophysics of the Academia Sinica, and his colleagues discovered the new moons, despite their small and faint appearance, using a technique called “shift and stacking.” This technique uses a set of images that move at the same speed as the moon moves across the sky, which enhances the signal from the moon. This allows moons that are too faint to be seen in the individual images to be revealed in the “stacked image.”

Astronomers have used this method to search for moons around the ice giants Neptune and Uranus, but this is the first time it has been applied to the solar system's second-largest planet, Saturn.

In the new study, the team used data collected by the Canada-France-Hawaii Telescope (CFHT) on Maunakea, Hawaii, from 2019 to 2021. The data helped them detect moons around Saturn as small as 2.5 kilometers in diameter.

While astronomers spotted a few moons in early 2019, they needed more information to confirm that they were moons and not asteroids approaching Saturn, so they monitored them for several years to make sure they were actually orbiting the gas giant.

The newly discovered moons are classified as “anomalous moons.” This term refers to objects that are gravitationally influenced by a planet and orbit that planet in large, flat or elliptical orbits that are tilted more than the orbits of regular moons. Saturn currently has 121 anomalous moons and 24 regular moons.

In February, Jupiter overtook Saturn as the “moon king” when 12 new moons were confirmed, bringing its total to 92. Saturn now has 145 moons, but the title could change hands again as astronomers’ moon-detecting technology improves.

Thu Thao (According to Space )

Source link