New Moons of Saturn

New moons of Saturn

This illustration shows the orbits of 20 newly-found moons of Saturn, giving the ringed planet a total of 82 moons. Saturn has overtaken Jupiter as the solar system’s satellite king.

(Image credit: Illustration: Carnegie Institution for Science.)


20 New Moons Found Around Saturn –

Snagging Satellite Record from Jupiter

Astronomers [have] just discovered 20 previously unknown Saturn moons, boosting the ringed planet’s tally of known satellites to 82 — three more than Jupiter’s. All 20 moons are tiny, measuring about 5 kilometers across. Seventeen of them have retrograde orbits, meaning they move around Saturn in the opposite direction to the planet’s rotation. These 17 all take more than three Earth-years to complete one Saturn lap, and the most far-flung one is the most distant Saturn satellite known, discovery team members said.

One of the three newly discovered “prograde” moons has an orbital period of more than three earth-years, while the other two complete one lap every two years or so.

The 17 retrograde moons appear to belong to the “Norse group” of Saturn satellites, which share the same basic orbital parameters. The two innermost prograde objects align with the “Inuit group,” and the outermost prograde moon among the new finds may belong to the “Gallic group,” but that’s unclear at the moment, researchers said.

Each of these satellite groups is likely evidence of a long-ago impact that destroyed a larger moon that had been orbiting in that general area.

“This kind of grouping of outer moons is also seen around Jupiter, indicating violent collisions occurred between moons in the Saturnian system or with outside objects such as passing asteroids or comets,” Scott Sheppard, of the Carnegie Institution for Science in Washington, D.C., said in a statement on 7th October announcing the discovery.

Sheppard led the discovery team. He and his colleagues — David Jewitt of the University of California, Los Angeles, and Jan Kleyna of the University of Hawaii — found the Saturn moons using the Subaru Telescope in Hawaii.

Discovery images

(Suggestion: use the zoom function to enlarge the image.)

The discovery images for the newly found very distant prograde moon of Saturn. They were taken on the Subaru telescope with about one hour between each image. The background stars and galaxies do not move, while the newly discovered Saturnian moon, highlighted with an orange bar, shows motion between the two images.

(Image credit: Courtesy of Scott Sheppard)

“Using some of the largest telescopes in the world, we are now completing the inventory of small moons around the giant planets,” Sheppard added. “They play a crucial role in helping us determine how our solar system’s planets formed and evolved.”

For example, the newly-found moons’ existence suggests that the impacts that created them occurred after Saturn was fully formed, Sheppard said. The gas giant was surrounded by a disk of dust and gas as it was taking shape. If these tiny moons had to plow through all that material on their way around Saturn, friction would have sapped their speed and sent them spiralling into the planet.

By Mike Wall – Science & Astronomy



 In This Post


20 New Moons Found Around Saturn

Our next public meeting

Babak Tafreshi delivers a superb lecture


Our next public meeting –

This Tuesday 22nd October 2019

Our telescopes will be operating


On 22nd October –

The Moon will not be visible.

Jupiter and Saturn will be in the west sky.

Mercury and Venus might briefly be seen low in the west immediately after sunset.

At 7.30pm the on-screen presentation will be –

Some of the Solar System’s moons –

Jupiter’s interesting volcanic moon Io

New moons of Jupiter and Saturn discovered


Astro-photographer delivers a superb lecture

Babak Tafreshi presented this year’s Beatrice Hill Lecture in Tauranga’s Otumoetai Baptist Auditorium on 11th October before an enthralled audience.

The annual Beatrice Hill lecture was organised by the Tauranga Astronomical Society (TAS) under the auspices of the Royal Astronomical Society of NZ, with whom TAS are affiliated.

Tafreshi presented an interesting on-screen programme on his work as an astro-photographer, explaining the dynamics of each photo and video.


Astro-photographer Babak Tafreshi presenting an on-screen programme in the Tauranga’s Otumoetai Baptist Auditorium on 11th October (above), and answers many questions from the appreciative audience (below). Note the Milky Way on the screen in the upper photo.


(Photos: TAS president David Greig)


Our next public meeting then –

Tuesday 22nd October

Fergusson Park Observatory, Tilby Drive, Matua, Tauranga.

Viewing – both astronomical and on-screen

On-screen program at 7.30pm –

Solar System’s moons


Admission to our meetings –

Door entry $5.

Members & children free.


Annual subscriptions are due –

$30 each adult

or $40 each family

$10 students.

Payment on-line or

cash at meetings.

No EFTPOS facility available.

On-line payment is easy, to –


Bank account number

03 0435 0659752 00

Please indicate

“Subscription” and your name.

Once payment is received your nametag(s) will be available at subsequent meetings.


telescope 1

Telescope viewing possible only with zero or minimum cloud cover.


Happy skies everyone.


Kevin Patmore


Tauranga Astronomical Society


TAS large





Affliated With:


With funding support from:


Slooh Space Camera


NASA astronomy picture of the day