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Saturns Moons: a Visual Guide

Updated on May 13, 2013
Saturn has well over 60 moons. It is like a mini solar system, with the moons orbiting like planets around the Sun.
Saturn has well over 60 moons. It is like a mini solar system, with the moons orbiting like planets around the Sun. | Source

The Moons of Saturn

Saturn is the favourite planet of many people. With the most extensive, complicated and elegant ring system in the Solar System, many people get caught up talking about the Rings of Saturn without even considering its moons. This is a shame, hopefully rectified here, as the moons of Saturn are wonderful worlds in their own right. Indeed, in our search for life, it may be a moon orbiting Saturn that harbours extraterrestrial life.

Saturn may have the highest number of moons in the solar system; to date, 62 moons have been confirmed.The Saturnian system has been visited by several probes including Pioneer, Voyager and Cassini. These probes have given us a glimpse of these weird and wonderful worlds - far from passive observers of their parent planet, the moons of Saturn actively create, shape and maintain its ring system.

Images of Iapetus

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The leading hemisphere of Iapetus (the hemisphere facing the direction of orbit) is so dark it can nearly disappear from view when observed from EarthThe trailing hemisphere is much brighter, although still has the huge impact craters that litter the 'dark side'The equatorial ridge is yet another mystery found on the enigmatic moon that is Iapetus
The leading hemisphere of Iapetus (the hemisphere facing the direction of orbit) is so dark it can nearly disappear from view when observed from Earth
The leading hemisphere of Iapetus (the hemisphere facing the direction of orbit) is so dark it can nearly disappear from view when observed from Earth | Source
The trailing hemisphere is much brighter, although still has the huge impact craters that litter the 'dark side'
The trailing hemisphere is much brighter, although still has the huge impact craters that litter the 'dark side' | Source
The equatorial ridge is yet another mystery found on the enigmatic moon that is Iapetus
The equatorial ridge is yet another mystery found on the enigmatic moon that is Iapetus | Source

Iapetus

Discovered in 1671, Iapetus is the third largest moon of Saturn. It is also one of the most mysterious.

Just like the force, Iapetus has a light side and a dark side - a characteristic that baffled scientists for years. When Cassini (the astronomer, not the space probe) first discovered the moon, he couldn't understand why he could only observe it when on one side of Saturn. When the moon should have been on the east of Saturn, it simply disappeared from view.

After a closer look by Cassini (the space probe, not the astronomer) in the early 21st Century, it is now believe that half of the surface is covered in a layer of carbon. This carbon is thought to have initially come from a meteorite impact, but following that an intriguing aspect of physics has accentuated the difference in colour.

Dark surfaces absorb heat and tend to be hotter than lighter, more reflective surfaces. This means that the dark side of Iapetus gets hotter than the light side. When combined with the very long rotation (more than 79 days) of the moon, the dark side spends so long in the sun that any ice on the surface evaporates. This leaves behind a carbon residue that makes the dark side darker. At the same time, the ice that evaporates from the dark side, falls as snow on the light side, making it even lighter and more reflective. The darker the dark side gets, the more heat it absorbs, and so makes itself darker: this creates a runaway effect that has divided the surface in two over millions of years.

Images of Titan

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Titan transiting SaturnInfrared image of the surface of Titan reveals some of the detail normally obscured by the thick smog-like atmosphereAn Artists impression of the surface of Titan, complete with methane lake
Titan transiting Saturn
Titan transiting Saturn | Source
Infrared image of the surface of Titan reveals some of the detail normally obscured by the thick smog-like atmosphere
Infrared image of the surface of Titan reveals some of the detail normally obscured by the thick smog-like atmosphere | Source
An Artists impression of the surface of Titan, complete with methane lake
An Artists impression of the surface of Titan, complete with methane lake | Source

Titan

Titan was discovered in 1655 and is the largest moon in the Saturnian system (the second largest in the solar system.) Titan is larger than Mercury and nearly the same size as Mars with an equatorial diameter of 5,150km (3,200 miles). Titan has an atmosphere four times more dense than our own on Earth that is around 600km (370miles) deep. Titan lies in a part of the Solar System that is so cold, methane condenses from a gas to a liquid; there is evidence of lakes of liquid methane on the surface of Titan

Images of Hyperion

Hyperion, as taken by Cassini on a close fly-by on September 26th 2005
Hyperion, as taken by Cassini on a close fly-by on September 26th 2005 | Source

Hyperion

Going on looks alone, this has to be my favourite moon out of all 170 in the Solar System. Discovered in 1848, Hyperion is not round (it was the first non round moon to be discovered) and has a battered surface analogous to the texture of a sponge. With its odd shape and chaotic, tumbling rotation, it is likely that Hyperion was a comet captured by Saturn's gravity.

Images of Dione

This view of the leading hemisphere of Dione clearly shows up a huge number of impact craters - some of them enormous. You can also see scars characteristic of ancient geologic activity.
This view of the leading hemisphere of Dione clearly shows up a huge number of impact craters - some of them enormous. You can also see scars characteristic of ancient geologic activity. | Source

Dione

Dione is the Saturnian moon most like our own Moon. It was discovered by Cassini (the astronomer, not the space probe) in 1684 and, while it looks like our own Moon, it is very different in composition.

A true ice-moon, Dione is two-thirds water, but at -190°C the frozen surface behaves like rock. The surface of the moon is covered in craters and ice-cliffs, but lacks the deep fissures of Europa meaning there is unlikely to be a liquid ocean underneath the surface. Just like our moon, Dione is tidally locked to Saturn; if you stood on the surface of Saturn (not possible but still) you would always see the same face of Dione.

Interestingly, among all the craters, there is evidence of tectonic activity since the formation of Dione: long scars adorn her surface similar to those at the boundaries of our own tectonic plates.

Images of Enceladus

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A mosaic image of Enceladus. You can see the mysterious 'Tiger Stripes' in the southern hemisphere. Each is around 130km long and 2km wide.The misty plume from an ice volcano in the 'Tiger Stripes' on the surface of Enceladus. It is thought these eruptions are what formed Saturns 'E-ring'Tidal forces act on fault lines in the Enceladus's icy shell causing the sides of the faults to rub back and forth against each other, producing enough heat to transform some of the ice into plumes of water vapour.
A mosaic image of Enceladus. You can see the mysterious 'Tiger Stripes' in the southern hemisphere. Each is around 130km long and 2km wide.
A mosaic image of Enceladus. You can see the mysterious 'Tiger Stripes' in the southern hemisphere. Each is around 130km long and 2km wide. | Source
The misty plume from an ice volcano in the 'Tiger Stripes' on the surface of Enceladus. It is thought these eruptions are what formed Saturns 'E-ring'
The misty plume from an ice volcano in the 'Tiger Stripes' on the surface of Enceladus. It is thought these eruptions are what formed Saturns 'E-ring' | Source
Tidal forces act on fault lines in the Enceladus's icy shell causing the sides of the faults to rub back and forth against each other, producing enough heat to transform some of the ice into plumes of water vapour.
Tidal forces act on fault lines in the Enceladus's icy shell causing the sides of the faults to rub back and forth against each other, producing enough heat to transform some of the ice into plumes of water vapour. | Source

Enceladus...in brief

Enceladus is a tiny moon (smaller in diameter than the length of the United Kingdom). It is the most reflective moon in the Solar System, reflecting almost all light that hits it. When first photographed by Voyager, scientists were in for a shock: vast areas of the surface had no craters. This could mean only one thing - the surface of the moon was new. But how could this be? Such a tiny moon could not possibly hold onto any meaningful internal heat to power geologic activity.

The smoothest regions of the moon were centered around four huge parallel trenches in the southern hemisphere: the Tiger Stripes. These stripes have an average temperature of -143°C, compared to an average surface temperature of -200°C. There ismore heat coming out of the south pole of the moon than the equator! And it is here that we find the answer to the smooth surface and high reflectivity (albedo) of Enceladus: ice volcanoes.

Not only do these icy geysers resurface the ground near the Tiger Stripes, but the material is blasted so high that it escapes the moon's gravity and is instead captured by Saturn's gravity. Enceladus not merely nestled in the E-ring...it is creating it.

The heat powering these eruptions is thought to be caused by friction. As the moon orbits Saturn in a huge oval, it gets stretched and flexed. Just like stretching and twisting a metal coat hanger, this causes quite a bit of heat. In the case of Enceladus, enough to melt ice and power ice geysers that fire at 800mph! There may even be an ocean under the Tiger Stripes that may harbour life...

Life on Saturn's Moons?

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    • FitnezzJim profile image

      FitnezzJim 4 years ago from Fredericksburg, Virginia

      I was struck by the feature of Iapetus. It looks like the ridge of a walnut, and I wondered how the light side/dark side relates to that.

    • alliemacb profile image

      alliemacb 4 years ago from Scotland

      Such an interesting hub. I love the images and it's great to learn something new. Voted up and awesome!

    • Austinstar profile image

      Austinstar 4 years ago from Somewhere in the universe

      How little we know about our own solar system. Thanks for sharing :-)

    • jainismus profile image

      Mahaveer Sanglikar 4 years ago from Pune, India

      Thank you for providing this great information with photographs.

    • Mmargie1966 profile image

      Mmargie1966 4 years ago from Gainesville, GA

      I really enjoyed this hub! I especially loved all the great pictures!

      Great Job...voted up

    • Nettlemere profile image

      Nettlemere 4 years ago from Burnley, Lancashire, UK

      Lapetus is very weird looking and Encelladus is beautiful - although they all have their attractions visually. I'm intrigued by the idea of a little moon the size of the UK.

    • alphajuno profile image

      alphajuno 4 years ago from League City, TX

      Great article on the moons of Saturn. We always get a kick out of viewing or photographing a planet's moons. I totally agree with you!

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