Saturns moons

Saturn is the six planet from the sun, it is one of the gas giants of the local solar system. Orbiting around saturn are millions and millions of objects and debris. Only 62 of these objects are considered to be moons of Saturn. Saturn's moons vary in size from moonlets-- roughly larger than one kilometer-- to Saturns largest moon Titan--which is larger than Mercury. Roughly 96% of the mass orbiting Saturn is the moon Titan, the six other planatery mass objects that orbit saturn make up roughly 4% of the mass, and the remaining 54 small moons and all of the rings make up a mear 0.4%.

Titan: Saturn's Largest Moon

Saturn's Largest Moon


The gases around Titan seem to be like the gases that were around Earth a long time ago. By learning about Titan, we will learn about Earth.

Discovered by Christiaan Huygens in 1655, it is the largest moon of Saturn and the second largest moon in the solar system, rivaled only by Jupiter's moon Ganymede. It is nearly as large as Mars, larger than the planet Mercury and possesses an atmosphere thicker than Earth's(1.6 bars, 60 percent greater than Earth's). Titan would unquestionably be considered a planet if only it orbited the Sun on its own. When scientists first began to understand what that atmosphere was made of -- primarily nitrogen, with a large component of methane and significant quantities of more complex organic molecules (smoggy atmosphere that gives Titan an orange cast.) -- they quickly realized that Titan would be a place where liquid methane or ethane could be raining from the skies.These hydrocarbon rich elements are the building blocks for amino acids necessary for the formation of life. Therefore scientists believe that Titan's environment may be similar to that of the Earth's before life began putting oxygen into the atmosphere. {C Thanks to Cassini-Huygens it is now known that Titan is a youthful planet whose surface is modified and its impact craters erased by the action of flowing liquids and possibly even a methane cycle of cloud formation, rain, runoff, and evaporation, akin to Earth's water cycle. The world revealed to Huygens' cameras as it descended to Titan's surface(temperature appears to be about -178°C (-289°F) on January 14, 2005 contains clear signs of river vallies and water-rounded rocks. And Cassini's Titan RADAR mapper is obtaining detailed views of channels and valleys, eroded impact craters, and windblown sand dunes that all speak of Titan's active geology.

170px Pixels scales of the composite images vary from 2 to 4 kilometers per pixel (1.2 to 2.5 miles per pixel)

The surface of Titan has historically been difficult to explore because the thick hazes of complex hydrocarbons that make its atmosphere so interesting also prevent a clear view to its surface. Titan stands out for how deep its atmosphere is, with layer upon layer of hazes making for a complicated series of obstacles to the sight of orbiting instruments. Its highest hazes may be 300 kilometers (190 miles) above the ground, nearly four times higher than the highest clouds on any other planet. And these thick hazes are made of piles of different compounds, a "witch's brew" of carbon, nitrogen, and hydrogen compounds.

This is a link to the Huygens probe descent to Titan.

Enceladus: Saturn's Weirdest Moon

Enceladus' -Saturn's 8th & 6th Largest Moon, During a flyby in July 2005, instruments on Cassini detected temperatures in this region that were much higher than expected. One scientist remarked that "This is as astonishing as if we'd flown past Earth and found that Antarctica was warmer than the Sahara".

Enceladus [en-SELL-ah-dus] is one of the innermost moons of Saturn. It was discovered in 1789 by the British astronomer William Herschel (who also discovered the planet Uranus). It is the sixth largest moon of Saturn, which is quite similar in size to Mimas but has a smoother, brighter surface. Enceladus reflects almost 100 percent of the sunlight that strikes it. Unlike Mimas, Enceladus displays at least five different types of terrain. Much of the surface of Enceladus resembles the terrain on many of the Solar System's moons; a mixture of flat plains and impact craters(35 km in diameter).However, a large area around the moon's South Pole consists of a fractured landscape similar in appearance to that found on Jupiter's moon Europa. Some of the cracks in the midst of this fractured terrain are remarkably smooth and somewhat blue in color, and have been nicknamed "Tiger Stripes". These stripes appear to be much younger than most of the rest of the surface of the moon. Some scientists think that cracks in the moon's icy surface may be allowing liquid water from beneath the surface to spew forth in huge geysers. These geysers might be comparable to the famous ones found in Yellowstone Park on Earth, but would be much larger and much colder. Volcanic activity (including ice geysers or volcanoes, which are referred to as examples of "cryovolcanism") is very rare in our Solar System. Only Earth, Jupiter's moon Io, possibly Neptune's moon Triton, and now perhaps Enceladus have been observed to be volcanically active.

The ice plumes on Enceladus give the small moon a tenuous atmosphere. The atmosphere is uneven, being much denser near the moon's South Pole than on the other side. Because of the small moon's weak gravity, the atmosphere must constantly be replenished to replace molecules that are swept off into space. Enceladus' super-reflective surface is probably the result of it being coated by fresh ice particles from the plumes, just as a blanket of new fallen snow can make landscapes on Earth incredibly bright and reflective. {C

Saturn's moon Enceladus as viewed by the Cassini spacecraft in July 2005.


It was named after a giant in greek mythology. He was the son of Gia and amongst the giants who warred against the giants. Despise it's name, Enceladus is a modest moon in size. Its diameter is around 505 km (314 miles), making it the sixth largest of Saturn's 59 moons. It rotates every 1.37 days and orbits Saturn in the same amount of time.

It is believed(by scientist)that Saturn's E ring is made up of ice particles from Enceladus. They think the a lot of the ice coming from Enceladus' southern polar regions escapes the moon's gravity and goes into orbit around Saturn, generating the planet's outermost ring. Furthermore, data from Cassini indicates that the Saturnian system is filled with oxygen atoms. Scientists postulate that as the water (H2O - hydrogen and oxygen) ice from Enceladus breaks down in space, it generates the observed oxygen atoms as well as hydrogen atoms. This claim is further supported by readings from Cassini's magnetometer instrument, which detected disruptions in Saturn's magnetic field in the neighborhood of Enceladus. Astronomers think ionized oxygen and hydrogen might be the cause of these disruptions.

Iapetus: The disappearing moon

Iapetus (eye-YAH-peh-tus) or Saturn VIII is the third largest moon orbiting Saturn, and the eleventh largest moon in the solar system. Iapetus is located on the inner side of what is called the Phoebe ring-- a large nearly invisible ring in the orbit of Saturn"s farthest-reaching moon Phoebe. Iapetus is roughly 4600 km in circumference and .

Saturn's moon Iapetus showing surface color variation

The moon bulges along the equator and flattens out at the polls with an equatorial mountain range, giving the moon a walnut like shape. Iapetus has a relatively low density and is made up of roughly 80% ice with a small rock core. The moon is tidally locked with Saturn, meaning the same part of Iapetus faces the planet all the time-- like our own moon. Iapetus amkes on rotation on its axis every 79.3 days and makes one orbit around Saturn every 79.3 days.Iapetus is most know for its striking color variations, one side a dark reddish brown, the other a stark white.

Iapetus was discovered by Giovanni Cassini in 1671. He first noticed the moon on the western side of Saturn. However, months later he tried to locate it on the eastern side he was unsuccessful. The pattern continued the following year. It took almost 25 years and an improved telescope for Cassini to see Iapetus on the eastern side of the planet. Giovanni surmised that the moon had a dark side (leading) and a light side (tailing), and was tidally locked with Saturn. The dark side of the moon was given the name Cassini Regio, in honor of its discoverer. Iapetus is also one of the Sidera Lodoicea, or Louisian stars, named after King Louis XIV of France, the Sun King.


Rhea is the second largest moon orbiting Saturn (behind Titan), and is the ninth largest moon in the solar system. The moon is one of the Sidera Lodoicea, discovered by Giovanni Cassini in 1672. Rhea is named for the Greek Titaness "Rhea - Mother of the Gods" and was named by John Herschel in 1847. Rhea makes one orbit around Saturn every 4.5 days and rotates on its axis one revolution every 4.5 days. Rhea is an ice moon, originally thought to be roughly 75% ice with a small rock core. However, recent tests done by the Cassini orbiter throws scientists into a

Saturns second largest moon, Rhea

debate. Fighting over whether Rhea has a core of solid rock or is just a giant ball of ice. Several scientists have written different controversial theories, none have been accepted by a majority. Further research and testing will have to be done to determine the cores properties. Some models suggest that Rhea is capable of harboring an internal body of water.

Rhea's surface temperature varies from 99 K to 53 K from full sunlight to behind Saturn. Its leading hemisphere is impact heavy and its trailing face has "wispy terrain". Upon further review the wispy terrain has turned into remnants of ice volcanism, and that itself has been disputed and then changed to ice cliffs formed from ice-plate tectonics, similar to that of Dione. Rhea has a very slight atmosphere, made up of oxygen and carbon dioxide.

In 2008, NASA announced that Rhea might have a tenuous ring system. The rings existence was instinctually discovered when changes in electron flows trapped by Saturn's magnetic field were observed by the Cassini orbiter. It is known that dust and particles can pass in Rhea's hill sphere so rings are not all that impossible. The possibility of Rhea's rings was strengthened when ultraviolet-bright spots were found along Rhea's equator that could possibly be from ring particle impacts. More evidence is needed to determine the validity of Rhea's rings.


Dione is the third largest moon in the Saturnian system and 15th largest in the solar system. It was one of the

Saturns moon Dione

Sidera Lodoicea, being that it was found by Giovanni Cassini in 1684. Dione is 1122 KM in diameter. Dione contains more mass than all the other known smaller moons in the solar system combined. Dione is the third densest moon of saturn(after titan and enceladus, who are denser due to gravitational compression). Having a composition of mostly water ice, Dione has to have a very dense rock matter core, and be at a ratio of almost 50/5o ice to rock. That being said Dione is a smaller and denser version of Rhea, the second largest moon of saturn. Dione is has a synchronous orbit, its rotates on its axis and around the planet one complete time every 2.7 days. Much like Rhea, Dione has a crater-filled leading hemisphere and a trailing hemisphere riddled with rugged cliff lines caled chasmatas.

Helene and Polydeuces


Dione is one of two moons that orbit around Saturn that has trojan moons. A trojan moons is a moon that stays at one of the LeGrange points of an large celestial body. Dione's two trojan moons are Helene and Polydeuces, lokated at L4 and L5. Helene leads the group(L4), 60 degrees infront of Dione, and Polydeuces brings up the rear, being roughly 60 degrees behind Dione (L5). Helene was discovered by Pierre Laques and Jean Lacacheauxin march of 1980 at the Pic de Midi Observatory in the French Pyrenees, Polydeuces was discovered by the Cassini


imaging Science Team in october of 2004. Helene is the larger of the two trojans, Helene is 36x32x30km and Polydeuces is more spherical being only 13 x13x13 km. while Helene is almost always 60 degrees away ahead odf Dione, Polydeuces cahnges degrees from as near as 39 degrees to 92 degrees .


Tetheys is the fourth largest moon orbiting Saturn. It is the 16th largest in the


solar system. Tethys is more massive than all the moons smaller than it in our solar system combined. Tethys, being a Sidera Lodoicea, means that it too was discovered by Giovanni Cassini. He discoverd Tethys in 1684 together with Dione. Tethys is 1071x1056x1052km in diameter. Tethys is not very dense, being one of the many ice moons of saturn. It is composed almsot entierly of waterice with a small rocky core. Tethys rotation is synchronous with Saturn, much like the earths moon. Tethys rotates on its axis and revolves aroun teh planet in 1.9 days.

Calypso and Telesto


Much like Dione, Tethys is one of two moons orbiting Saturn that has trojan moons in its L points. Calypso and Telesto are Tethys' trojan moons. Leading the group is Telesto, first discovered by a group of scientists in April of 1980. th surface of Telesto is relativly smooth looking, possibly coated with a fine dust. Calyppso is teh other trojan moon co-orbital with tethys. often called tetheys trojan. Like amy other saturnina small moons, calypso is irregualarly


shaped and has many over lapping craters. And there seems to be a fine dust around on the surface, that smooths out the look of the impact craters.

The Other Moons of Saturn

Saturn has 62 known moons. Of them, Titan is the largest, and is the second-largest in our solar system (Jupiter's Ganymede is largest). The other satellites have icy surfaces and many craters. Mimas has one crater that spans one quarter of it's diameter. Most of the moons, which are small, were probably captured asteroids, and did not form with Saturn.

Saturn's Moon Epimetheus


Pan is the closest satellite to Saturn. That is about all that we know about it.

Next comes Atlas. Atlas serves a very important function: Its orbit is at the edge of Saturn's A-ring, and Atlas keeps the A-ring in place, so the particles cannot go beyond its orbit

Saturn's Moon Prometheus

Next out are Prometheus and Pandora. Prometheus and Pandora serve a joint purpose which is not unlike Atlas: Prometheus guards the inside of the F-ring, while Pandora guards the outside.

Saturn's Moon Janus

Next come Epimetheus and Janus. Scientists think that these two moons were once part of a single moon that was later blasted apart. This claim is supported by the fact that their orbits are within thirty miles of each other.

Next comes Mimas. This is a unique moon because it has a hugecrater that covers fully one quarter of its entire surface..

Saturn's Moon Mimas

Next out are Enceladus, Tethys, Telesto, Calypso, Helene, Dione, and Rhea. Dione looks very much like our moon, except that it contains ice. Tethys, Telesto, and Calypso all share the same orbit. Rhea is the second largest moon of Saturn, and also looks like our moon..

Titan is the second-largest moon in the solar system. It is also one of the only three that have an atmosphere (Jupiter's Io and Neptune's Triton are the other two). Out of the other two, Titan certainly has the thickest. In fact, its clouds are so thick that the moon is like Venus; it is impossible to see the ground. Therefore, we know very little about this moon, except it has a thick orange cloud-cover, and an atmosphere thicker than Earth's.

The next three moons are Hyperion, Iapetus, and Phoebe. Hyperion looks like a hamburger, and has a crater that covers one third of its bottom side. Iapetus has one side that reflects light, but the other side is covered in a dark material The other 13 moons all orbit outside of Iapetus' orbit, but a few are inside of Phoebe's. They were discovered in 2000 by a team of astronomers who were examining old photographs of Saturn and the area around Saturn. They are tiny, and some orbit retrograde, meaning that they orbit in the direction opposite the planet's spin - an almost certain indication that they are captured asteroids rather than being native to the system. They are currently being called S/2000 S#, with the # ranging from 1 to 12, and S/2003 S1. They will eventually be given names by the International Astronomical Union, the only official naming group.

Saturnian Moon Fiction