Whether Saturn's Rings are Young or Old, its Moons are as Ancient as the Planet Itself

The moons of Saturn, from left to right: Mimas, Enceladus, Tethys, Dione, Rhea; Titan in the background; Iapetus (top) and irregularly shaped Hyperion (bottom). Some small moons are also shown. All to scale. Credit: NASA/JPL/Space Science Institute

Saturn is best known for two things: its iconic ring structures and its large system of natural satellites. Currently, 146 moons and moonlets have been discovered orbiting the ringed giant, 24 of which are regular satellites. These include the seven largest moons, Titan, Rhea, Iapetus, Dione, Tethys, Enceladus, and Mimas, which are icy bodies believed to have interior oceans. In addition, there are unresolved questions about the age of these satellites, with some suspecting that they formed more recently (like Saturn’s rings, which are a few hundred million years old).

To address these questions, an international team of astronomers created a series of high-resolution simulations coupled with improved estimates of Trans-Neptunian Object (TNO) populations. This allowed them to construct a chronology of impacts for Saturn’s most heavily cratered regular satellites – Mimas, Enceladus, Tethys, Dione, and Rhea. This established age limits of 4.1 and 4.4 billion years for all five, with the two innermost moons appearing more youthful than the outer three. These results could have significant implications for our understanding of the formation and tidal evolution of moons in the outer Solar System.

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Saturn’s Rings Warm Up its Atmosphere

Composite image of hydrogen emissions observed on Saturn gathered between 1980 and 2017 by Voyager 1, Cassini, and Hubble. A near-ultraviolet image taken by Hubble in 2017 being used to calibrate the almost 40 years of data. The amount of reflected ultraviolet (UV) sunlight is measured in brightness, with the rings reflecting the least amount UV sunlight. The dark spot at the pole is Saturn's spin axis. (Credit: NASA, ESA, Lotfi Ben-Jaffel (IAP & LPL))

Saturn’s rings are one of the most well-known features throughout astronomy. While much is known about them, they still make headlines from time to time. This includes a recent study involving an international team of researchers that could help paint a clearer picture of the interaction between the gas giant and the massive ring system that encircles it.

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It's Time for Mysterious Spokes to Appear in Saturn's Rings

The Hubble Space Telescope captured this image of Saturn in February, 2023. Image Credit: STScI

The Hubble Space Telescope recently captured the appearance of several asymmetrical ‘spokes’ rising above the rings of Saturn, marking a coming change in season for the ringed gas giant. The spokes are made of charged ice particles bulging up and away from the rest of the rings. Researchers aren’t sure exactly what causes the spokes, but they suspect it has something to do with the planet’s powerful magnetic fields.

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Saturn Might Have Torn a Moon Apart to Make its Rings

Saturn's rings in all their glory. Image from the Cassini orbiter as Saturn eclipsed the Sun. Image Credit: By NASA / JPL-Caltech / Space Science Institute
Saturn's rings in all their glory. Image from the Cassini orbiter as Saturn eclipsed the Sun. Image Credit: By NASA / JPL-Caltech / Space Science Institute

Saturn is a world of surprises. The Voyager 1 and 2 flybys and later on, the Cassini mission, opened our collective eyes to intricate details in its rings and atmosphere. They also gave us up-close and personal looks at those amazing moons. But, one thing they didn’t show us was Saturn’s proposed moon Chrysalis. That’s because it doesn’t exist. Well, actually, it is there, but in the form of those dazzling rings.

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Jupiter's Giant Moons Prevent it From Having Rings Like Saturn

Saturn and its system of rings, acquired by the Cassini probe. Credit: NASA/JPL-Caltech

When the name Saturn is uttered, what comes to mind? For most people, the answer would probably be, “its fabulous system of rings.” There’s no doubt they are iconic, but what is perhaps lesser-known is that Jupiter, Uranus, and Neptune all have ring systems of their own. However, whereas Saturn’s rings are composed mainly of ice particles (making them highly reflective), Jupiter’s rings are composed mainly of dust grains. Meanwhile, Uranus and Neptune have rings of extremely dark particles known as tholins that are very hard to see. For this reason, none of the other gas giants get much recognition for their rings.

However, the question of why Jupiter doesn’t have larger, more spectacular rings than Saturn has been bothering astronomers for quite some time. As the larger and more massive of the two bodies, Jupiter should have rings that would dwarf Saturn’s by comparison. This mystery may have finally been resolved thanks to new research by a team from UC Riverside. According to their study, Jupiter’s massive moons (aka. Jupiter’s Galilean Moons) prevented it from developing a big, bright, beautiful ring system that would put Saturn’s to shame.

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Animation Shows how Saturn’s Rings Move at Different Speeds

Saturn's F ring is extremely narrow compared to the historic A, B and C rings. It measure just a few hundred kilometers across. Credit: NASA/Cassini

Saturn’s rings are one of the most recognized and revered celestial objects known to the human race. From a distance, they look like a disk of layered crystal or multicolored disks within disks that wrap around Saturn’s hazy umber face. When viewed up close, we see that these rings are actually particles of water ice (from microns to icebergs), as well as silicates, carbon dioxide, and ammonia.

We would also noticed that the rings have some interesting orbital mechanics. In fact, each ring has a different orbit that is the result of its proximity to Saturn (i.e., the closer they are, the faster they orbit). To illustrate what this complex system look like, NASA Fellow Dr. James O’Donoghue created a stunning animation that shows how each of Saturn’s major ring segments (A-Ring to F-Ring) orbit together around the planet.

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Enceladus Causes Snowfall On Other Moons of Saturn

Stunningly beautiful Enceladus has a subsurface ocean. Image Credit: NASA/JPL/Space Science Institute

Radar evidence shows that geysers on Enceladus are ejecting water that turns to snow. The snow not only falls back on Enceladus’ surface, but also makes its way to its neighboring moons, Mimas and Tethys, making them more reflective. Researchers are calling this a ‘snow cannon.’

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Here’s Hubble’s Newest Image of Saturn

The latest view of Saturn from NASA's Hubble Space Telescope captures exquisite details of the ring system — which looks like a phonograph record with grooves that represent detailed structure within the rings — and atmospheric details that once could only be captured by spacecraft visiting the distant world. Hubble's Wide Field Camera 3 observed Saturn on June 20, 2019, as the planet made its closest approach to Earth, at about 845 million miles away. This image is the second in a yearly series of snapshots taken as part of the Outer Planets Atmospheres Legacy (OPAL) project. OPAL is helping scientists understand the atmospheric dynamics and evolution of our solar system's gas giant planets. In Saturn's case, astronomers will be able to track shifting weather patterns and other changes to identify trends. Credits: NASA, ESA, A. Simon (GSFC), M.H. Wong (University of California, Berkeley) and the OPAL Team

Hubble has captured a new image of Saturn that makes you wonder if it’s even real. The image is so crisp it makes it look like Saturn is just floating in space. Which it is.

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Mimas Pushes Through Saturn’s Rings Like a Snowplow

Saturn's rings and moons have been the subject of scientific debate. A 2019 study showed that the migration of Saturn's moons has widened the Cassini Division in Saturn's rings. Image Credit: Cassini, Dante, Baillié and Noyelles

Saturn’s moon Mimas is the smallest of the gas giant’s major moons. (Saturn has 62 moons, but some of them are tiny moonlets less than 1 km in diameter.) Two new studies show how Mimas acted as a kind of snow-plow, widening the Cassini division between Saturn’s rings.

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Saturn’s Rings are Only 10 to 100 Million Years Old

Saturn's rings in all their glory. Image from the Cassini orbiter as Saturn eclipsed the Sun. Image Credit: By NASA / JPL-Caltech / Space Science Institute
Saturn's rings in all their glory. Image from the Cassini orbiter as Saturn eclipsed the Sun. Image Credit: By NASA / JPL-Caltech / Space Science Institute

Can you imagine the Solar System without Saturn’s rings? Can you envision Earth at the time the dinosaurs roamed the planet? According to a new paper, the two may have coincided.

Data from the Cassini mission shows that Saturn’s rings may be only 10 to 100 million years old. They may not have been there during the reign of the dinosaurs, and may in fact be a fairly modern development in our Solar System.

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