{"id":55418,"date":"2024-03-07T09:44:06","date_gmt":"2024-03-07T09:44:06","guid":{"rendered":"http:\/\/666711b2-22c0-41de-8fa1-a5e89a6a69c2"},"modified":"2024-03-07T11:32:56","modified_gmt":"2024-03-07T11:32:56","slug":"a-beginners-guide-to-the-rings-of-saturn-one-of-the-solar-systems-most-beautiful-features","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/a-beginners-guide-to-the-rings-of-saturn-one-of-the-solar-systems-most-beautiful-features\/","title":{"rendered":"A beginner’s guide to the rings of Saturn, one of the Solar System’s most beautiful features"},"content":{"rendered":"

Amazing facts about Saturn’s rings, including when they were discovered and how old they are. <\/p>

By Jenny Winder\n <\/p>

Published: Thursday, 07 March 2024 at 09:44 AM<\/p>

\n\n

The rings of Saturn are possibly the most iconic feature in the Solar System, and over the decades various planetary probes have revealed a lot about these intriguing structures, including clues as to how they formed, what they’re made of, and how they have changed over time.<\/p>

Other planets may have rings, but none as spectacular as Saturn\u2019s<\/a>.<\/p>

Galileo was first to observe the rings around Saturn in 1610, but he was unsure if he was seeing two moons or whether Saturn had handles or \u2018ears\u2019.<\/p>

And why did they seem to come and go every year or so?<\/p>

Cassini captured this image of the moon Daphnis orbiting within the 42km Keeler Gap. The waves in the edges of the gap are caused by the moon\u2019s gravitational pull. Credit: NASA\/JPL-Caltech\/Space Science Institute<\/figcaption><\/figure>
In 1656 Christiaan Huygens was first to suggest that Saturn had a ring that was not attached to the planet, and in 1675 Giovanni Domenico Cassini identified the formation as being composed of a series of rings and gaps, identifying the A and B rings and the largest gap, which was named the Cassini Division after him.<\/p>
It was thought the rings were solid or liquid, but in 1859 James Clerk Maxwell proved they were made of particles and were orbiting Saturn independently. <\/p>
The main rings have been named in the order of their discovery; so the C ring was discovered in 1850, the D ring in 1933 and the E ring in 1967.<\/p>
The diffuse Phoebe ring, discovered in 2009, extends an enormous 6\u201316.2 million km from Saturn.<\/p>
**How many rings does Saturn have?<\/strong><\/h2>** $\"A$ <\/figure>
There are 7 main rings around Saturn, labelled A,B,C,D,E,F and G, but many of these have their own subdivisions, gaps, structures and moonlets within.<\/p>
From inner to outermost, the main structures in Saturn’s rings are:<\/p>
D, C and B rings<\/li>
Cassini Division<\/li>
A ring<\/li>
Roche Division<\/li>
F ring<\/li>
Janus\/Epimetheus ring<\/li>
G ring<\/li>
Methone and Anthe ring arcs<\/li>
Pallene ring<\/li>
E ring<\/li>
Phoebe ring<\/li><\/ul>
**Why are Saturn’s rings flat?<\/strong><\/h2>** $\"A$
A Cassini image showing Titan, Saturn\u2019s largest moon, behind the planet\u2019s rings. The smaller moon Epimetheus can be seen in the foreground. Image Credit: NASA\/JPL\/Space Science Institute<\/figcaption><\/figure>
Why are the rings around Saturn so flat, being 250,000km wide and only a few tens of metres thick? The answer lies in how the rings evolve over time.<\/p>
As each ring particle travels around Saturn there are many collisions between the particles.<\/p>
Any particles that are in inclined orbits have a higher probability of colliding with other members, and over time they will be eliminated.<\/p>
Eventually the system settles down into a disc, leaving the flat ring system we see today.<\/p>
This disc-forming process happens not only in planetary rings but also elsewhere in the Universe, such as in young solar systems and the discs that surround black holes.<\/p>
As more and more ring particles settle into the disc, collisions increase and the members diminish in size.<\/p>
We also see smaller and smaller particles as a result of seeing it through higher resolution telescopes.<\/p>
What space missions have visited Saturn?<\/strong><\/h2>
$\"A$
A view of Saturn\u2019s rings captured by the Cassini spacecraft on 21 July 2016. Just below rings can be spotted Saturn\u2019s tiny moon Mimas. Credit: NASA\/JPL-Caltech\/Space Science Institute<\/figcaption><\/figure>
4 missions have had close encounters with Saturn so far. Pioneer 2<\/a>was first, passing by in 1979 when it discovered the very narrow F ring.<\/p>
Normally collisions between particles would spread the ring both inward towards the planet and outward to create a wide, diffuse ring. But the F ring is kept narrowly confined by the influence of two shepherd moons, called Prometheus and Pandora.<\/p>
In 1980, Voyager 1<\/a> identified the G ring, and the following year Voyager 2 discovered several smaller ringlets when it passed by.<\/p>
In July 2004, the Cassini mission<\/a> began its 13-year visit to the planet, discovering many new moons and ringlets.<\/p>
$\"A$
A view of the rings at Saturn captured by Voyager 2, 22 August 1981, from a distance of 2.5 million miles. Credit: NASA \/ JPL-Caltech<\/figcaption><\/figure>
What are Saturn’s rings made of?<\/strong><\/h2>
The particles in Saturn’s rings consist of almost pure water ice; this makes them extremely bright.<\/p>
Saturn\u2019s albedo, the amount of light it reflects, varies from \u20130.5 when the rings are edge-on to 0.9 when they are fully open.<\/p>
The particles range from the size of a sand grain to 10m or more in diameter. The total mass of the rings is equal to that of Saturn\u2019s moon Mimas.<\/p>
The gaps are not well-defined empty spaces, but are areas where particle density drops. The largest of these, the Cassini Division, is 4,700km wide.<\/p>
$\"An$
An image of Saturn from Voyager 2. The picture has been colour-enhanced to show in bright details the planet\u2019s surface and the features of the rings. Clearly visible is the gap between the A and B rings, called the Cassini Division. (Credit: NASA\/JPL)<\/figcaption><\/figure>
The rings orbit in the same direction as Saturn but at different rates, the inner rings faster than the outer ones in accordance with Kepler\u2019s third law.<\/p>
The main rings extend from 7,000km to 80,000km from the planet\u2019s equator, yet they are only an average of 10m thick. <\/p>
The disappearance of the rings that so perplexed Galileo is due to the 27\u00b0 tilt of Saturn\u2019s axis to the ecliptic.<\/p>
From Earth we see Saturn’s rings from different angles as both planets orbit: first from below, then they almost disappear as we see them edge-on, then they widen again as we see them from above and then they appear edge on again, so the rings seem to vanish roughly every 15 years.<\/p>
$\"A$
A view of Saturn’s rings captured by the Cassini spacecraft. Credit: Source: NASA\/JPL-Caltech\/Space Science Institute<\/figcaption><\/figure>
How did Saturn’s rings form?<\/strong><\/h2>
The origin of Saturn\u2019s rings has been hotly debated.<\/p>
One theory is that they are all that remains of one of Saturn\u2019s moons that was ripped apart by gravitational forces when its orbit decayed, bringing it too close to its parent planet. That would mean the rings are younger than the planet.<\/p>
Another theory is that the rings are the same age as the planet, being remnants of the nebula from which Saturn formed.<\/p>
In April 2017 at the end of Cassini\u2019s tour of the Saturn system, the spacecraft performed the Grand Finale phase of its mission<\/a>, passing between Saturn and its rings 22 times before diving into and burning up in the planet\u2019s atmosphere.<\/p>
Data from these acrobatics on the rings\u2019 brightness and purity revealed they may have formed just 100 million years ago, when dinosaurs still ruled the Earth.<\/p>
$\"A$
A view of Saturn captured by the Cassini spacecraft on 2 January 2010 from about 2.3 million km away. Credit: NASA\/JPL-Caltech\/Space Science Institute<\/figcaption><\/figure>
If they were older, the theory goes, they would have been darkened over time by cosmic dust, although other scientists suggest that recycling of material within the rings, as particles collide, break apart and reform, could dilute any pollutants. <\/p>
However they were formed, the rings are continually losing material in the form of an icy rain falling onto Saturn, at a rate of a swimming pool full of material every half hour.<\/p>
There\u2019s still plenty of time to view them: it\u2019s estimated they won\u2019t be gone for good for 100 million years.<\/p>
Images of Saturn’s rings<\/strong><\/h2>
$\"Saturn\u2019s$
Saturn\u2019s spokesHubble Space Telescope, 21 December 2023Credit: NASA, ESA, STScI, A. Simon (NASA-GSFC)<\/figcaption><\/figure><\/div><\/div>
$\"Image$
Image of Saturn and its ring spokes captured by the Hubble Space Telescope on 22 October 2023. Credit: NASA, ESA, STScI, Amy Simon (NASA-GSFC)<\/figcaption><\/figure><\/div><\/div>
$\"NASA's$
NASA’s Cassini spacecraft captured these views of a propeller feature in Saturn’s A ring on 21 February 2017. Credit: NASA<\/figcaption><\/figure><\/div><\/div>
$\"Saturn$
Saturn and its rings, as seen by the James Webb Space Telescope, 30 June 2023Credit: NASA, ESA, CSA, STScI, Matt Tiscareno (SETI Institute), Matt Hedman (University of Idaho), Maryame El Moutamid (Cornell University), Mark Showalter (SETI Institute), Leigh Fletcher (University of Leicester), Heidi Hammel (AURA)<\/figcaption><\/figure><\/div><\/div>
$\"Saturn\u2019s$
Saturn\u2019s tilt means its rings are becoming more edge on. By late 2025 they\u2019ll be virtually impossible to see (for a few months). Credit: NASA<\/figcaption><\/figure><\/div><\/div>
$\"A$
A 2006 observation of Saturn’s E ring by the Cassini spacecraft. The E ring is fed with icy particles via plumes erupting from the subsurface ocean of Saturn’s icy moon Enceladus. The moon’s shadow is seen as a dark dot within the ring. Credit: NASA\/JPL\/Space Science Institute<\/figcaption><\/figure><\/div><\/div>
$\"Jupiter,$
Jupiter, Saturn, Uranus and Neptune, as seen by the Hubble Space Telescope. Credit: NASA, ESA, A. Simon (Goddard Space Flight Center), and M.H. Wong (University of California, Berkeley) and the OPAL team<\/figcaption><\/figure><\/div><\/div>
$\"Saturn$
Saturn photographed by John Chumack, Dayton, Ohio, USA, 20 August 2021<\/figcaption><\/figure><\/div><\/div>
$\"Saturn$
Saturn and its moons Tethys, Dion and Rhea, as seen by Voyager 2 in August 1981. Credit: NASA\/JPL-Caltech<\/figcaption><\/figure><\/div><\/div>
$\"A$
A view of Saturn from above its north pole, made from 36 images obtained on 10 October 2013. Credit: NASA\/JPL-Caltech\/SSI\/Cornell<\/figcaption><\/figure><\/div><\/div>
$\"A$
A view of Saturn’s rings captured by the Cassini spacecraft. Credit: Source: NASA\/JPL-Caltech\/Space Science Institute<\/figcaption><\/figure><\/div><\/div>
$\"A$
A view of Saturn’s rings captured by Voyager 2, 22 August 1981, from a distance of 2.5 million miles. Credit: NASA \/ JPL-Caltech<\/figcaption><\/figure><\/div><\/div>
$\"A$
A labelled diagram of Saturn’s rings. Credit: NASA\/JPL-Caltech\/SSI<\/figcaption><\/figure><\/div><\/div>
$\"Saturn's$
Saturn’s rings, as seen by the Cassini spacecraft. Credit: NASA\/JPL-Caltech\/Space Science Institute<\/figcaption><\/figure><\/div><\/div>
$\"Hubble$
NASA, ESA and Erich Karkoschka (University of Arizona)<\/figcaption><\/figure><\/div><\/div>
$\"Images$
Images of Saturn’s polar aurora captured by the Hubble Space Telescope on 24, 26 and 28 January 2005.Credit: NASA\/Hubble\/Z. Levay and J. Clarke<\/figcaption><\/figure><\/div><\/div>
$\"Moon$
Moon Titan appears in front of Saturn in an image captured by NASA\u2019s Cassini spacecraft. Credit:\u00a0NASA\/JPL-Caltech\/Space Science Institute<\/figcaption><\/figure><\/div><\/div>
$\"\"$
By taking images in different wavelengths, Hubble has given researchers a new perspective of familiar sights such as this picture of Saturn taken in the ultraviolet. Credit: NASA\/ESA<\/figcaption><\/figure><\/div><\/div>
$\"An$
An enhanced colour image of Daphnis embedded in Saturn’s rings, kicking up waves of material. The images in the mosaic were taken in visible light, using the Cassini’s narrow-angle camera at a distance of approximately 28,000km from the ring moon. Image scale is 170m per pixel. Credit: Tilmann Denk at Freie Universit\u00e4t in Berlin.<\/figcaption><\/figure><\/div><\/div>
$\"The$
The NASA\/ESA Hubble Space Telescope has provided images of Saturn in many colors, from black-and-white, to orange, to blue, green, and red. But in this picture, image processing specialists have worked to provide a crisp, extremely accurate view of Saturn, which highlights the planet’s pastel colors. Bands of subtle colour – yellows, browns, grays – distinguish differences in the clouds over Saturn, the second largest planet in the solar system.<\/figcaption><\/figure><\/div><\/div>
$\"\"$ <\/figure><\/div><\/div>
$\"\"$ <\/figure><\/div><\/div>
$\"\"$
8th March 2014. Spectacular view of Saturn\u2019s rings with Pandora. The gravitational pull from the moon helps confine the outer F ring and keep it from spreading. (Credit: NASA\/JPL-Caltech\/Space Science Institute)<\/figcaption><\/figure><\/div><\/div>
$\"Saturn$
Saturn and two of its moons photographed in 1980 by Voyager 1. The moons, Tethys (closest to the planet) and Dione, are visible as bright spots in space next to the gas giant. Tethys’s shadow can also be seen on Saturn itself. (Credit: NASA\/JPL)<\/figcaption><\/figure><\/div><\/div>
$\"An$
An image of Saturn from Voyager 2. The picture has been colour-enhanced to show in bright details the planet\u2019s surface and the features of the rings. Clearly visible is the gap between the A and B rings, called the Cassini Division. (Credit: NASA\/JPL)<\/figcaption><\/figure><\/div><\/div>
$\"A$
A view of the northern hemisphere of Saturn in 2016, as it nears its summer solstice in May 2017. Image Credit: NASA\/JPL-Caltech\/Space Science InstituteCredit: NASA\/JPL-Caltech\/Space Science Institute<\/figcaption><\/figure><\/div><\/div>
$\"A$
A view of Saturn\u2019s rings captured by the Cassini spacecraft on 21 July 2016. Just below rings can be spotted Saturn\u2019s tiny moon Mimas.Credit: NASA\/JPL-Caltech\/Space Science Institute<\/figcaption><\/figure><\/div><\/div><\/div>

How many rings does Saturn have?<\/strong><\/h2><\/figure>There are 7 main rings around Saturn, labelled A,B,C,D,E,F and G, but many of these have their own subdivisions, gaps, structures and moonlets within.<\/p>From inner to outermost, the main structures in Saturn’s rings are:<\/p>