Titan: Facts About Saturn's Largest Moon Titan: Facts About Saturn's Largest Moon By Nola Taylor Redd, Space.com Contributor | June 30, 2016 04:56pm ET MORE This view shows a close up of toward the south polar region of Saturn's largest moon, Titan, and show a depression within the moon's orange and blue haze layers near the south pole. NASA’s Cassini spacecraft snapped the image on Sept. 11, 2011 and it was released on Dec. 22. Credit: NASA/JPL-Caltech/Space Science Institute Titan is Saturn's largest moon and the second largest in the solar system (after Ganymede of Jupiter). It is the only moon in the solar system with clouds and a dense, planet-like atmosphere. Scientists believe that conditions on Titan are similar to Earth's early years (the main difference is that, because it is closer to the sun, Earth has always been warmer).

According to NASA , "In many respects, Saturn's largest moon, Titan, is one of the most Earth-like worlds we have found to date." Titan stats Diameter: 3,200 miles (5,150 kilometers), about half the size of Earth and almost as large as Mars Surface temperature: minus 290 Fahrenheit (minus 179 degrees Celsius), which makes water as hard as rocks and allows methane to be found in its liquid form Surface pressure: Slightly higher than Earth's pressure. Earth's pressure at sea level is 1 bar while Titan's is 1.6 bars. Orbital period: 15,945 days NASA's Cassini spacecraft peers through the murk of Titan's thick atmosphere in this view, taken with Cassini's narrow-angle camera on Sept. 25, 2008. Credit: NASA/JPL/Space Science Institute Other Titan facts Titan's name comes from Greek mythology. The Titans were elder gods who ruled the universe before the Olympians came to power, according to the Theoi Project website. The moon was discovered by Dutch astronomer Christiaan Huygens in 1655.

The Huygens lander probe sent to the moon aboard NASA's Cassini spacecraft by the European Space Agency is named in his honor. Huygens was the first human-built object to land on Titan's surface. [ Amazing Photos of Titan ] Titan's diameter is 50 percent larger than that of Earth's moon . Titan is larger than the planet Mercury but is half the mass of the planet. Titan's mass is composed mainly of water in the form of ice and rocky material. Titan has no magnetic field. Atmosphere of Titan Titan is surrounded by an orange haze that kept its surface a mystery for Earth's scientists until the arrival of the Cassini mission. Titan's atmosphere extends about 370 miles high (about 600 kilometers), which makes it a lot higher than Earth's atmosphere. Because the atmosphere is so high, Titan was thought to be the largest moon in the solar system for a long time. It wasn't until 1980 that Voyager was close enough to discover it was actually smaller than Ganymede. Titan's atmosphere is active and complex , and it is mainly composed of nitrogen (95 percent) and methane (5 percent).

Titan also has a presence of organic molecules that contain carbon and hydrogen, and that often include oxygen and other elements similar to what is found in Earth's atmosphere and that are essential for life. There is an unsolved mystery surrounding Titan's atmosphere: Because methane is broken down by sunlight, scientists believe there is another source that replenishes what is lost. One potential source of methane is volcanic activity, but this has yet to be confirmed. Titan's atmosphere may escape to space in a similar way that Earth's atmosphere does . The Cassini spacecraft has detected polar winds that draw methane and nitrogen (charged with interactions with light) out along Saturn's magnetic field and out of the atmosphere. A similar process is believed to happen on Earth with our own magnetic field. Magic Island There is an abundance of methane lakes , which are mainly concentrated near its southern pole. In 2014, scientists found a transient feature they playfully referred to as " Magic Island ." It's possible that nitrogen bubbles formed in Titan's oceans sit on the surface for a period of time, creating a temporary island that eventually dissipates.

"What I think is really special about Titan is that it has liquid methane and ethane lakes and seas, making it the only other world in the solar system that has stable liquids on its surfaces," Jason Hofgartner, a planetary scientist at Cornell University, told Space.com in 2014. "It not only has lakes and seas, but also rivers and even rain. It has what we call a hydrological cycle, and we can study it as an analog to Earth's hydrological cycle — and it's the only other place we know of where we can do that." Large areas of Titan's surface are covered with sand dunes made of hydrocarbon. Dunes on Titan may resemble the Namibian desert in Africa. Because methane exists as a liquid on Titan, it also evaporates and forms clouds, which occasionally causes methane rain . Clouds of methane ice and cyanide gas float over the moon's surface. "Titan continues to amaze with natural processes similar to those on the Earth, yet involving materials different from our familiar water," Cassini deputy project scientist Scott Edgington, of NASA's Jet Propulsion Laboratory in Pasadena, California, said in a statement .

Sunlight is quite dim on Titan, and climate is driven mostly by changes in the amount of light that accompanies the seasons. Titan, moon of Saturn - The Solar System on Sea and Sky (NASA/JPL/Space Science Institute) The Giant Titan [TY-tun] is the fifteenth of Saturn's moons and is the largest. It is also the second largest moon in the Solar System. Titan was names after the ancient race of giants in Greek Mythology. They were the children of Uranus and Gaia, who sought to rule the heavens but were overthrown by the family of Zeus. Titan was discovered in 1655 by the Dutch astronomer Christiaan Huygens. Titan was once thought to be the largest planet in the Solar System, but recent discoveries have shown that the Moon's thick atmosphere hides a smaller rocky surface that is slightly smaller than Jupiter's moon, Ganymede. Though it is only the second largest moon in the Solar System, it is still larger than the planets Mercury and Pluto. False color radar image of Titan showing surface features (NASA/JPL/Space Science Institute) (NASA/JPL) The Moon With an Atmosphere Even before the Voyager encounters with Saturn, astronomers thought that Titan might have an atmosphere.

They also thought that there might be oceans of liquid methane on the Moon's surface. When the Voyager spacecraft finally arrived, all that could be seen of Titan was a dense and impenetrable layer of clouds in a thick atmosphere. Titan was found to have an atmosphere denser than that of Earth and Mars. The atmospheric pressure at the surface is believed to be about 1.6 bars, about 60% greater that on Earth. The atmosphere is composed primarily of Nitrogen with traces of other hydrocarbons such as ethane, hydrogen cyanide, and carbon dioxide. This gives it a rich, orange color. These atmospheric elements are necessary building blocks for life. Astronomers believe that Titan may resemble the Earth at an early stage in its development. They also think that Titan is a prime candidate for the possibility of extraterrestrial life. Titan's surface temperature averages -289°F (-178° C). Panoramic view of the surface of Titan as seen by the European Space Agency's Huygens probe as it descended to the surface. Huygens was the first spacecraft to land on an alien moon.

(ESA/NASA/JPL/University of Arizona) Features of Titan Titan is the only known moon with a fully developed, planet-like atmosphere. Unfortunately, this thick atmosphere prevented us from learning much about its surface features during the Voyager missions. What we do know is that it appears to be composed of about half water ice and half rocky material. It is believed to be similar in composition to many of Saturn's other moons, but is much denser because of its large size and higher gravity. Titan's atmosphere is believed to have two cloud layers at about 125 miles (200 km) and 186 miles (300 km) above the surface. Titan has no known magnetic field, and sometimes orbits outside Saturn's magnetosphere. This exposes it directly to the solar wind, which may ionize and remove particles from the atmosphere. In 2004, the Cassini probe arrived at Saturn and dropped a probe called Huygens into Titan's atmosphere. It landed and sent back images of the surface as well as measurements of Titan's atmosphere. Cassini was then able to map Titan's surface using radar, as was done on the Magellan mission to Venus.

As amazing as these images were, they only posed more questions than answers. But thanks to Cassini, we have now witnessed some of the most detailed images yet of the ringed planet and her moons. Liquid Lakes Because Titan has a thick atmosphere containing hydrocarbons, scientists had long theorized that there could be lakes of liquid methane and ethane on its surface. When the Voyager spacecraft encountered Titan in 1980 and 1981, they were unable to see beneath the moon's thick layer of clouds. NASA's Cassini spacecraft arrived at Saturn in 2005 armed with radar. The radar instruments were able to see through the clouds and map the moon's surface. Radar images taken in 2006 proved the existence of liquid lakes on Titan. These are the first liquid lakes seen anywhere in the Solar System besides Earth. The largest of these newly discovered lakes is larger than the Great Lakes on Earth. In addition to the lakes, channels resembling rivers were observed. This provided strong evidence of liquid rain. Scientists believe that rain composed of liquid methane and ethane regularly falls across Titan's surface. In fact, the weather on Titan may be very similar to weather patterns on Earth.

Titan Is A Moon Of The Solar System Planet Saturn. ?K Atmospheric characteristicspressure 146.7 kPa Nitrogen 98.4 percent methane 1.6 percent Titan is the only moon in our solar system to have a dense atmosphere. Until very recently, this atmosphere inhibited understanding of Titan's surface, but the moon is currently undergoing study by the Cassini-Huygens mission, and new information about it is accumulating. Titan was discovered on March 25, 1655 by the Dutch astronomer Christiaan Huygens, and was the first satellite in the Solar System to be discovered after the Galilean moons of Jupiter. On July 27, 2006, NASA confirmed the presence of hydrocarbon lakes in Titan's north polar region. Name Titan. Huygens named his discovery simply Saturni Luna (Latin for "Saturn's moon", which can also be written Luna Saturni) (De Saturni Luna observatio nova, 1656; XV).

Later, Giovanni Domenico Cassini named the four moons he discovered (Tethys, Dione, Rhea and Iapetus) Sidera Lodoicea ("the stars of Louis") to honour king Louis XIV. Astronomers fell into the habit of referring to them as Saturn I through Saturn V. Other epithets used were the "Huygenian satellite of Saturn" (or "Huyghenian"), or the "sixth satellite of Saturn" (Saturn VI, still in use) (in order of distance from Saturn, once Mimas and Enceladus were also discovered in 1789). The name "Titan" and the names of all seven satellites of Saturn then known come from John Herschel (son of William Herschel, discoverer of Mimas and Enceladus) in his 1847 publication Results of Astronomical Observations made at the Cape of Good Hope, wherein he suggested the names of the Titans, sisters and brothers of Cronos (the Greek Saturn), be used. Visibility from Earth Titan has a Magnitude between +7.9 and +8.7 and reaches an angular distance of about 20 Saturn radii from Saturn.

It can be observed through small telescopes (diameter greater than 5 cm) or strong binoculars. It subtends a disk 0.8 arcseconds in diameter. Physical characteristics of the moon Titan. Titan in false color showing surface details and atmosphere. At 5,150 km across, Titan is larger than the planet Mercury (though less massive) and the Dwarf planet Pluto and is the second largest natural satellite in the solar system after Ganymede. Prior to the arrival of Voyager 1 in 1980, Titan was thought to be slightly larger than Ganymede, an error resulting from the haze in its atmosphere which extends around 880 km above the surface and is almost opaque to visible light. Hence, visual observations of Titan before discovery of this haze overestimated its diameter. Internal structure of the moon Titan. Titan's internal structure. Titan's diameter and mass (and thus its density) are similar to Jovian moons Ganymede and Callisto. Based on its bulk density of 1.88 g/cmÂï¿½, Titan bulk composition is half water ice and half rocky material.

It is probably differentiated into several layers with a 3400 km (2,040 mi) rocky center surrounded by several layers composed of different crystal forms of ice. Its interior may still be hot and there may be a liquid layer consisting of water and ammonia between the ice crust and the rocky core. Though similar in composition to Rhea and the rest of Saturn's moons, it is denser due to gravitational compression. Atmosphere of the moon Titan. Layers of haze seen in a colorized ultraviolet image of Titan's night-side limb. True-color image of layers of haze in Titan's atmosphere. Titan is the only known moon with a fully developed atmosphere that consists of more than just trace gases. The presence of a significant atmosphere was first discovered by Gerard P. Kuiper in 1944 using a spectroscopic technique that yielded an estimate of an atmospheric partial pressure of methane of the order of 100 millibars (10 kPa).

Since that time, observations from Voyager space probes have shown that the Titanian atmosphere is denser than Earth's, with a surface pressure more than one and a half times that of our planet, and supports an opaque cloud layer that obscures Titan's surface features at visible wavelengths. The haze that can be seen in the picture to the right contributes to the moon's anti-greenhouse effect and lowers the temperature by reflecting sunlight away from the satellite. The thick atmosphere blocks most visible wavelength light from the sun and other sources from reaching Titan's surface. It is so thick, in fact, and the gravity is so low, that a human could fly through it by flapping "wings" attached to his arms . The Huygens probe was unable to detect the direction of the sun during its descent, and although it was able to take images from the surface, scientists say the process was like photographing asphalt at dusk.

The atmosphere is 98.4% Nitrogen the only dense nitrogen-rich atmosphere in the solar system aside from our own with the remaining 1.6% composed of methane and only trace amounts of other gases such as hydrocarbons (including Ethane, diacetylene, methylacetylene, cyanoacetylene, Acetylene, propane), Argon, carbon dioxide, Carbon monoxide, cyanogen, hydrogen cyanide and helium. The hydrocarbons are thought to form in Titan's upper atmosphere in reactions resulting from the breakup of methane by the Sun's ultraviolet light, producing a thick orange smog. Titan has no magnetic field and sometimes orbits outside Saturn's magnetosphere, directly exposing it to the solar wind. This may ionize and carry away some molecules from the top of the atmosphere. The nitrogen ratio of14N to15N is 183 compared with the Earth's average of 272. In the methane the isotope ratio of12C/13C is 82.3 compared with the earth standard of 89.9.

The isotope ratio of H/D is 3.6 x 103 compared with 3.0 x 103 on Earth. The depletion of the lighter isotope of nitrogen indicates atmospheric escapes where as the carbon and the hydrogen are far less depleted. The ratio of argon to nitrogen is 100 times less than in Earth's atmosphere. Possible cloud of Ethane (red) over Titan's north pole (marked NP). From all available data several theoretical models and experiments for the development of the Titan atmosphere have been derived. The high UV-radiation and high energy electrons are an energy source for many chemical reactions in the atmosphere. The hydrogen compounds ammonia and methane undergo dehydrogenation, forming complex organic compounds, nitrogen and hydrogen which is lost over cosmological time. The absence of ammonia and the presence of methane, although they should have a similar half life, indicates a source for methane on Titan. Clathrates (methane incorporated into ice), comets and a Fischer Tropsch like synthesis are suggestions for the abundance of methane . The most recent flyby has suggested the existence of a large cloud over Titan's north pole, existing at a height of 40km.

At this altitude it is cold enough for ethane to freeze, and the detected size of these particles is only 1-3 microns, suggesting again ethane, rather than methane which is also known to condense in the atmosphere of Titan. The downdrafts at high northern latitudes are strong enough to drive these particles towards the surface. A theory is that it is currently raining (or if cool enough - snowing) on the north pole. When the seasons switch, ethane will begin to condense over the south pole. Climate of the moon Titan. At the surface, Titan's temperature is about 94 K (-179 ÂºC, or -290.2 ÂºF). At this temperature water ice does not sublimate, so the atmosphere is nearly free of water vapor. Scattered variable clouds punctuate an overall haze in Titan's atmosphere. These clouds are probably composed of methane, ethane or other simple organics. Other more complex chemicals in small quantities must produce the orange color as seen from space. The findings of the Huygens probe indicate that Titan's atmosphere periodically rains liquid methane and other organic compounds onto the moon's surface .

It is possible that areas of Titan's surface may be coated in a tar-like layer of organic precipitate called tholin, but this has not been confirmed. The presence of argon 40 was also discovered in the atmosphere, evidence of cryovolcanism producing a "lava" of water ice and ammonia . Later, a methane-spewing volcano was spotted in close-up images, and Titanian volcanism is now believed to be a significant source of the methane in the atmosphere; previously hypothesized methane oceans now appear to be virtually absent . The October 2004 Cassini flyby photographed bright, high clouds at Titan's south pole, but they do not appear to be methane, as had been expected. This discovery has baffled scientists, and studies are currently underway to determine the composition of the clouds and decide whether our understanding of Titan's atmosphere needs to be revised . Observations by Cassini of the atmosphere made in 2004 suggest that Titan is a "super rotator", like Venus, with an atmosphere that rotates much faster than its surface. Surface features of the moon Titan. "Xanadu" is the bright region at the centre-right of this Cassini image.

The Cassini mission has revealed that Titan's surface is relatively smooth. The few objects that seem to be impact craters appeared to have been filled in, perhaps by raining hydrocarbons or volcanoes. The area mapped so far appears to have no height variation greater than 50 meters (165 feet); however, radar altimetry has so far only covered part of the north polar region. Titan's surface is marked by broad regions of bright and dark terrain. These include a large, highly reflective area about the size of Australia identified in infra-red images from the Hubble Space Telescope and the Cassini spacecraft. This region is named Xanadu and appears to represent an area of relatively high ground. There are dark areas of similar size elsewhere on the moon, observed from the ground and by Cassini; it had been speculated that these are methane or Ethane seas, but Cassini observations seem to indicate otherwise (see below). Cassini has also spotted some enigmatic linear markings, which some scientists have suggested may indicate Tectonic activity, as well as regions of bright material cross-cut by dark lineaments within the dark terrain.

In order to understand Titanian surface features better, the Cassini spacecraft is currently using radar altimetry and synthetic aperture radar imaging to map portions of Titan during its close fly-bys of the moon. The first images have revealed a complex, diverse geology with both rough and smooth areas. There are features that seem volcanic in origin, which probably disgorge water mixed with ammonia. There are also streaky features that appear to be caused by windblown particles. Liquids on Titan. It has long been believed that Titanian lakes or even seas of methane might exist on the surface. However, while many of the surface features could be explained as the products of flowing liquids, and while features that look like lakes have been discovered at the poles, conclusive evidence for the presence of liquids on Titan's surface at the present time remains absent. When the Cassini probe arrived in the Saturnian system, it was hoped that hydrocarbon lakes or oceans might be detectable by reflected sunlight from the surface of any liquid bodies, but no specular reflections were observed. Image taken during the descent of Huygens, showing hills riddled with channels, and what appears (deceptively) to be a shoreline.

The photographs taken during the January 14, 2005 landing on Titan by the Huygens probe do not show any open areas of liquid, but they strongly indicate the presence of liquids in the recent past, showing pale hills crisscrossed with dark drainage channels that lead into a wide, flat, darker region. It was initially thought that the dark region might be a lake of a fluid or at least tarry substance. However, it is now clear that Huygens landed on the dark region, and that it is solid. There are no indications of liquids at the Huygens landing site. A penetrometer studied the composition of the surface as the craft impacted it, and it was initially reported that the surface was similar to loose sand, or wet clay. However, subsequent analysis of the data suggests that this reading was likely caused by Huygens displacing a large pebble as it landed, and that the surface is better described as a 'sand' made of ice grains. The images taken after the probe's landing show a flat plain covered in pebbles. The pebbles, which may be made of water ice, are somewhat rounded, which may indicate the action of fluids on them.

The existence of lakes on Titan thus remains unconfirmed, and some scientists now believe that many of the moon's features are caused by cryovolcanism rather than running liquids. However, it has been hypothesized that Huygens landed during a dry season on Titan, and that periods of heavy methane rain in the recent past could form lakes that subsequently evaporate. The length of the intervals between rainy periods on Titan are unknown, and scientists stress that Huygens sampled only one tiny site on this planet-sized moon, which is insufficient for evaluating the entire body. Two recent developments have kept the possibility of Titanian lakes alive at Titan's south pole, where clouds have been observed to cluster. An enigmatic dark feature at the pole, named Ontario Lacus has been identified as a possible lake created by precipitation from the clouds that cluster at the pole. A possible shoreline has also been identified at the pole via radar imagery. Radar image of northern latitudes of Titan, showing the dark features identified as lakes.

Following a flyby on July 22, in which the Cassini spacecraft's radar imaged the northern latitudes (which are currently in winter), a number of large, dark (and thus smooth to radar) patches were seen dotting the surface near the pole. Scientists speculate that these features are almost certainly the long sought hydrocarbon lakes of Titan. Some of the lakes appear to have channels running in or out of them, which are just as smooth. Ethane and methane may be liquids near Titan's poles, which are cold enough for these gases to condense. Repeated coverage of these areas should prove whether they are truly liquid, as any changes that correspond with wind blowing on the surface of the liquid, would alter the roughness of the surface and be visible in the radar. NASA recently confirmed that there is ice from hydrocarbon rain at the north polar area. Impact craters on the moon Titan. Radar SAR and imaging data from Cassini have revealed a relative paucity of impact craters on Titan's surface, suggesting a youthful surface.

To date, only three impact craters have been confirmed, include a 440-km wide multi-ring impact basin named Menrva (seen by ISS as a bright-dark concentric pattern), a smaller 80-km wide flat-floored crater named Sinlap, and a 30-km crater with a central peak and dark floor named Ksa. RADAR and Cassini imaging have also revealed a number of "crateriforms", circular features on the surface of Titan that maybe impact related, but lack certain features that would make identification certain. For example, a 90-km wide ring of bright, rough material known as Guabonito has been observed by Cassini. This feature is thought to be an impact crater filled-in by dark, windblown sediment. Several other similar features have been observed in the dark Shangri-la and Aaru regions. RADAR observed several circular features that may be craters in the bright region Xanadu during Cassini's April 30, 2006 flyby of Titan. cryovolcanism of the moon Titan. One of the first radar images of Titan's complex surface.

The circular feature at left, Ganesa Macula, is thought to be a cryovolcanic dome. Scientists have speculated that conditions on Titan resemble those of early Earth, though at a much lower temperature. Evidence of volcanic activity from the latest Cassini mission suggests that temperatures are probably much higher in hotbeds, enough for liquid water to exist. Argon 40 detection in the atmosphere indicates that volcanoes spew plumes of water and ammonia. Dark terrain of the moon Titan. Titan's sand dunes (below), compared with dunes on Earth's surface (above). In the first images of Titan's surface taken by Earth-based telescopes in the early 2000s, large regions of dark terrain were revealed straddling Titan's equator. Prior to the arrival of Cassini, these regions were thought to be seas of organic matter like tar or seas of liquid hydrocarbons. However, Radar images captured by the Cassini spacecraft has instead revealed some of these regions to be extensive plains covered in longitudinal sand dunes.

The sand dunes are believed to be formed by wind generated as a result of tidal forces from Saturn on Titan's atmosphere, which are 400 times stronger than the tidal forces of the Moon on Earth. The tidal winds cause dunes to build up in long parallel lines, with Titan's zonal winds aligning the dunes west-to-east. The dunes break this pattern around mountains, where the wind direction is shifted. Widespread evidence has also recently been found to support the claim that lakes of hydrocarbons do in fact exist on Titan's North pole during the second of several planned Cassini spacecraft flybys. (see section Liquids on Titan). The sand on Titan might have formed when liquid methane rained and eroded the ice bedrock, possibly in the form of flash floods. Alternatively, the sand could also have come from organic solids produced by photochemical reactions in Titan's atmosphere. Huygens landing site of the moon Titan. Huygens image from Titan's surface. The Huygens probe landed just off the easternmost tip of a bright region now called Adiri, and photographed pale hills with dark 'rivers' running down to a dark plain.

Current understanding is that the hills (also referred to as highlands) are composed mainly of water ice. Dark organic compounds, created in the upper atmosphere by the ultraviolet radiation of the Sun, may rain from Titan's atmosphere. They are washed down the hills with the methane rain and are deposited on the plains over geological time scales. Huygens landed on a dark plain covered in small rocks and pebbles, which are composed of water ice. The two rocks just below the middle of the image on the right are smaller than they may appear. The left-hand one is 15 centimeters (about 6 inches) across, and the one in the center is 4 centimeters (about 1.5 inches) across, at a distance of about 85 centimeters (about 33 inches) from Huygens. There is evidence of erosion at the base of the rocks, indicating possible fluvial activity. The surface is darker than originally expected, consisting of a mixture of water and hydrocarbon ice. It is believed that the 'soil' visible in the images is precipitation from the hydrocarbon haze above. List of geological features on Titan: Exploration of Titan. Cassini image of Epimetheus and Titan.

Titan was examined by both Voyager 1 and Voyager 2, with Voyager 1's course being diverted specifically to make a closer pass of Titan. Unfortunately Voyager 1 did not possess any instruments that could penetrate Titan's haze, an unforseen factor. Many years later, intensive digital processing of images taken through Voyager 1's orange filter did reveal hints of the light and dark features now known as Xanadu and the Sickle, but by then they had already been observed in the infrared by the Hubble Space Telescope. Voyager 2 took only a cursory look at Titan. The Voyager 2 team had the option of steering the spacecraft to take a detailed look at Titan or to use another trajectory which would allow it to visit Uranus and Neptune. Given the lack of surface features seen by Voyager 1, the latter plan was implemented.

The Cassini-Huygens spacecraft reached Saturn on July 1, 2004 and has begun the process of mapping Titan's surface by radar; The Cassini probe flew by Titan on October 26, 2004 and took the highest-resolution images ever of the moon's surface, at only 1,200 kilometers, discerning patches of light and dark that would be invisible to the human eye. Huygens landed on Titan on January 14, 2005, discovering that much of the moon's surface features seem to have been formed by flowing fluids at some point in the past. Present liquid on the surface may be found near the north pole, in the form of many lakes that were recently discovered by Cassini. Life on Titan. Artistic representation of a view from the surface of Titan, with dune fields, lakes, channels and Saturn in the background. Scientists believe that the atmosphere of early Earth is similar in composition to the atmosphere on Titan. Consequently, many hypotheses have developed that attempt to bridge the step from chemical to biological evolution.

The Miller-Urey experiment and several following experiments have shown that with an atmosphere similar to that of Titan and the addition of UV radiation, complex molecules and polymer substances like tholins can be generated. The reaction starts with dissociation of nitrogen and methane forming hydrocyan and ethine. Further reactions have been studied extensively. All of these experiments have led to the suggestion that enough organic material exists on Titan to start a chemical evolution like on Earth, if liquid water is available for longer periods. Several theories suggest that liquid water from an impact could be preserved under a frozen isolation layer, or even that water ammonia oceans can exist deep below the surface. The limited solar energy would only provide energy for a limited biota. For Titan, the search for life is at an early stage. The Cassini-Huygens mission was not equipped to provided evidence for complex organics or even biology. Due to this lack of experimental data, scientists have found no hint of life so far. Future missions are not planned and after adding the time for planning, construction, and the voyage itself, further scientific results are several decades in the future. Of course, we must keep in mind that terrestrial life is, so far, the ONLY clear case of life we have". Titan in fiction.

Titan is one of the most popular extraterrestrial settings in science fiction other than Earth's Moon and the planets. Cassini: Mission to Saturn: Overview Magnetosphere Science Overview From 20 degrees above the ring plane, Cassini’s wide angle camera shot 75 exposures in succession for this mosaic showing Saturn, its rings and a few of its moons a day and a half after exact Saturn equinox, when the sun’s disk was exactly overhead at the planet’s equator. Image credit: NASA/JPL/Space Science Institute Before Cassini, we had only brief glimpses of the discoveries awaiting us at Saturn. Pioneer 11 and Voyagers 1 and 2 conducted flybys decades ago, taking pictures, measurements and observations as they zoomed past. These missions shed new light on Saturn’s complicated ring system, discovered new moons and made the first measurements of Saturn’s magnetosphere. But these quick encounters didn’t allow time for more extensive scientific research. Cassini changed all that. It began the first in-depth, up-close study of Saturn and its system of rings and moons in 2004.

It became the first spacecraft to orbit Saturn, beginning a mission that yielded troves of new insights over more than a decade. The Saturnian system proved to be rich ground for exploration and discoveries, and Cassini's science findings changed the course of future planetary exploration. "We're looking at a string of remarkable discoveries -- about Saturn's magnificent rings, its amazing moons, its dynamic magnetosphere and Titan's surface and atmosphere," said Linda Spilker, Cassini's project scientist. "Some of the mission highlights so far include discovering that Titan has Earth-like processes and that the small moon Enceladus has a hot-spot at its southern pole, plus jets on the surface that spew out ice crystals, and liquid water beneath its surface." Cassini let us see beneath Titan's thick orange haze. This synthetic aperture radar image taken by Cassini has abundant evidence for flowing liquids, from sinuous, wide river channels to shorter, more chaotic drainage patterns. Image credit: NASA/JPL-Caltech/ASI Studying Saturn’s Many Moons Some of the most surprising scientific findings have come from encounters with Saturn’s fascinating, dynamic moons. Cassini's observations of Saturn's largest moon, Titan, have given scientists a glimpse of what Earth might have been like before life evolved.

They now believe Titan possesses many parallels to Earth, including lakes, rivers, channels, dunes, rain, clouds, mountains and possibly volcanoes. The data from the Cassini spacecraft and the European Space Agency's Huygens probe, which plunged through Titan's dense, smoggy atmosphere to land on its surface in 2005, have generated hundreds of scientific articles and been the subject of special issues of the world’s most important scientific journals. Enceladus, too, proved to be a rich source of discovery. The spray of icy particles from the surface jets forms a towering plume three times taller than the width of Enceladus itself. Cassini confirmed that the plume feeds particles into Saturn's most expansive ring, the E ring. The spacecraft has come as close as 15 miles (25 kilometers) from the moon's icy surface during its investigation, revealing the presence of a global subsurface ocean that might have conditions suitable for life. Saturn's moon Enceladus backlit by the sun show the fountain-like sources of the fine spray of material that towers over the south polar region.

Image credit: NASA/JPL/Space Science Institute Extending the Mission The Cassini mission has seen two mission extensions, allowing for more flybys, investigations and measurements, over a longer span of time. When its initial four-year tour of the Saturn system was complete in 2008, the Cassini-Huygens saga had brought a new dimension of understanding to the complex and diverse Saturn system. The two-year Cassini Equinox Mission brought continued excitement. During that first extended mission, the spacecraft made 60 additional orbits of Saturn, 26 flybys of Titan, seven of Enceladus, and one each of Dione, Rhea and Helene. The Equinox mission allowed for observations of Saturn's rings as the sun lit them edge-on, revealing a host of never-before-seen insights into the rings' structure. Since 2010, the spacecraft has conducted a second, seven-year-long, extended mission called the Cassini Solstice Mission. This final mission will conclude with a phase known as The Grand Finale -- 22 deep dives between Saturn's cloud tops and innermost ring before it plunges into the giant planet's atmosphere. Why “Equinox” and “Solstice”?

Saturn’s axis is tilted with respect to its orbit around the sun, similar to Earth. And just like on Earth, Saturn has seasons as a result of this tilt. But on Saturn, one season lasts seven Earth years. Cassini initially arrived just after Saturn's northern winter solstice, and the Solstice Mission continues until a few months past the northern summer solstice in May 2017. A complete seasonal period on Saturn has never been studied at this level of detail. The Solstice mission schedule allows for an additional 155 orbits around the planet, 54 flybys of Titan and 11 flybys of the icy moon Enceladus. Science Instruments Cassini carries 12 science instruments to collect a wide range of information about the Saturnian environment. These sophisticated devices take images across the infrared, visible and ultraviolet light spectra, detect dust particles, and characterize Saturn's plasma environment and magnetosphere. Titan: Gigantic Moon or Dwarf Planet? Shows > Kingdoms of the Giants: Realms of Jupiter & Saturn Titan: Gigantic Moon or Dwarf Planet?

By Steve Spaleta | January 11, 2010 12:29pm ET The second largest moon in our Solar System has one of the supposed primary requirements for life: an active liquid cycle. But Titan's liquid isn't water. credit : SPACERIP / Space.com Saturn's Largest Moon Titan: A World Much Like Earth - YouTube Saturn's Largest Moon Titan: A World Much Like Earth Want to watch this again later? Sign in to add this video to a playlist. Need to report the video? Sign in to report inappropriate content. The interactive transcript could not be loaded. Loading... Rating is available when the video has been rented. This feature is not available right now. Please try again later. Uploaded on Mar 5, 2010 ... Titan Saturn System Mission - Titan Canyon Country. Titan Saturn System Mission (TSSM) is a joint NASA/ESA proposal for an exploration of Saturn and its moons Titan and Enceladus, where many complex phenomena have been revealed by the recent CassiniHuygens mission.

--- • --- With an estimated NASA cost of $2.5 Billion (FY07), TSSM was originally proposed to launch in 2020, get gravity assists from Earth and Venus, and arrive at the Saturn system in 2029. The 4-year prime mission would include a two-year Saturn tour, a 2-month Titan aero-sampling phase, and a 20-month Titan orbit phase. The Titan Saturn System Mission (TSSM) was officially created in January 2009 by the merging of the ESA's Titan and Enceladus Mission (TandEM) with NASA's Titan Explorer 2007 study, although plans to combine both concepts date at least back to early 2008 TSSM was competing against the Europa Jupiter System Mission (EJSM) proposal for funding since then, however in February 2009 it was announced that NASA/ESA had given EJSM priority ahead of TSSM, although TSSM will continue to be studied for a later launch date, probably sometime in the 2020s.

Detailed assessment reports of the mission elements as well as a specific concept for the lake landing-module called Titan Mare Explorer (TiME) have been released in February and October 2009, respectively. • --- Since its discovery in 1655 by the Dutch astronomer Christiaan Huygens, the surface of Titan has remained largely a mystery. A thick, cloudy atmosphere, largely impenetrable by telescopes and cameras, envelops Saturn's largest moon. In December 2004, the robotic Huygens probe detached from the Cassini spacecraft and descended into Titan's thick, hazy atmosphere in January of 2005. Lasting a mere 3 hours in the cold atmosphere and on the surface of Titan (about minus 178 degrees Celsius, or minus 289 degrees Fahrenheit), the probe revealed a thick atmosphere, land masses with signs of erosion, and seas of methane on the surface. The Huygens probe came to rest on what appeared to be a floodplain, surrounded by rounded cobbles of water ice. About 100 kilometers smaller in diameter than Jupiter's moon Ganymede, Titan is the second largest moon in our solar system.

With an equatorial radius of 2,575 kilometers (1,600 miles), Titan is larger than both the Earth's moon and the planet Mercury. Titan orbits Saturn at a distance of about 1.2 million kilometers (745,000 miles), taking almost 16 days to complete a full orbit. Titan is of great interest to scientists because it is the only moon in the solar system known to have clouds, a mysterious, thick, planet-like atmosphere and surface lakes. NASA - Cassini Finds Likely Subsurface Ocean on Saturn Moon Cassini Finds Likely Subsurface Ocean on Saturn Moon 06.28.12 This artist's concept shows a possible scenario for the internal structure of Titan, as suggested by data from NASA's Cassini spacecraft. Image credit: A. Tavani › Full image and caption › Related animation The colorful globe of Saturn's largest moon, Titan, passes in front of the planet and its rings in this true color snapshot from NASA's Cassini spacecraft. Image credit: NASA/JPL-Caltech/Space Science Institute › Full image and caption PASADENA, Calif.

-- Data from NASA's Cassini spacecraft have revealed Saturn's moon Titan likely harbors a layer of liquid water under its ice shell. Researchers saw a large amount of squeezing and stretching as the moon orbited Saturn. They deduced that if Titan were composed entirely of stiff rock, the gravitational attraction of Saturn would cause bulges, or solid "tides," on the moon only 3 feet (1 meter) in height. Spacecraft data show Saturn creates solid tides approximately 30 feet (10 meters) in height, which suggests Titan is not made entirely of solid rocky material. The finding appears in today's edition of the journal Science. "Cassini's detection of large tides on Titan leads to the almost inescapable conclusion that there is a hidden ocean at depth," said Luciano Iess, the paper's lead author and a Cassini team member at the Sapienza University of Rome, Italy. "The search for water is an important goal in solar system exploration, and now we've spotted another place where it is abundant." Titan takes only 16 days to orbit Saturn, and scientists were able to study the moon's shape at different parts of its orbit.

Because Titan is not spherical, but slightly elongated like a football, its long axis grew when it was closer to Saturn. Eight days later, when Titan was farther from Saturn, it became less elongated and more nearly round. Cassini measured the gravitational effect of that squeeze and pull. Scientists were not sure Cassini would be able to detect the bulges caused by Saturn's pull on Titan. By studying six close flybys of Titan from Feb. 27, 2006, to Feb. 18, 2011, researchers were able to determine the moon's internal structure by measuring variations in the gravitational pull of Titan using data returned to NASA's Deep Space Network (DSN). "We were making ultrasensitive measurements, and thankfully Cassini and the DSN were able to maintain a very stable link," said Sami Asmar, a Cassini team member at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The tides on Titan pulled up by Saturn aren't huge compared to the pull the biggest planet, Jupiter, has on some of its moons.

But, short of being able to drill on Titan's surface, the gravity measurements provide the best data we have of Titan's internal structure." An ocean layer does not have to be huge or deep to create these tides. A liquid layer between the external, deformable shell and a solid mantle would enable Titan to bulge and compress as it orbits Saturn. Because Titan's surface is mostly made of water ice, which is abundant in moons of the outer solar system, scientists infer Titan's ocean is likely mostly liquid water. On Earth, tides result from the gravitational attraction of the moon and sun pulling on our surface oceans. In the open oceans, those can be as high as two feet (60 centimeters). While water is easier to move, the gravitational pulling by the sun and moon also causes Earth's crust to bulge in solid tides of about 20 inches (50 centimeters). The presence of a subsurface layer of liquid water at Titan is not itself an indicator for life. Scientists think life is more likely to arise when liquid water is in contact with rock, and these measurements cannot tell whether the ocean bottom is made up of rock or ice. The results have a bigger implication for the mystery of methane replenishment on Titan.

"The presence of a liquid water layer in Titan is important because we want to understand how methane is stored in Titan's interior and how it may outgas to the surface," said Jonathan Lunine, a Cassini team member at Cornell University, Ithaca, N.Y. "This is important because everything that is unique about Titan derives from the presence of abundant methane, yet the methane in the atmosphere is unstable and will be destroyed on geologically short timescales." A liquid water ocean, "salted" with ammonia, could produce buoyant ammonia-water liquids that bubble up through the crust and liberate methane from the ice. Such an ocean could serve also as a deep reservoir for storing methane. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The mission is managed by JPL for NASA's Science Mission Directorate in Washington. DSN, also managed by JPL, is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions. Cassini's radio science team is based at Wellesley College in Massachusetts.

JPL is a division of the California Institute of Technology in Pasadena. For more information about the mission, visit: and . Titan Titan Titan is the fifteenth of Saturn 's known satellites and the largest: orbit : 1,221,830 km from Saturn diameter : 5150 km mass : 1.35e23 kg In Greek mythology the Titans were a family of giants, the children of Uranus and Gaia , who sought to rule the heavens but were overthrown and supplanted by the family of Zeus. Discovered by Christiaan Huygens in 1655. It was long thought that Titan was the largest satellite in the solar system but recent observations have shown that Titan's atmosphere is so thick that its solid surface is slightly smaller than Ganymede's . Titan is nevertheless larger in diameter than Mercury and larger and more massive than Pluto . Surface view One of the principal objectives of the Voyager 1 mission was the study of Titan. Voyager 1 came within 4000 km of the surface. We learned more in the few minutes of that fly-by than in the previous 300 years.

Then in late 2004, the Cassini orbiter began a series of close encounters with Titan, taking data with many instruments. And in January 2005, the Huygens probe actually landed on the surface of Titan and sent back images from the surface. Titan is similar in bulk composition to Ganymede , Callisto , Triton and (probably) Pluto , ie about half water ice and half rocky material. It is probably differentiated into several layers with a 3400 km rocky center surrounded by several layers composed of different crystal forms of ice. its interior may still be hot. Though similar in composition to Rhea and the rest of Saturn 's moons, it is denser because it is so large that its gravity slightly compresses its interior. Smoggy Titan Alone of all the satellites in the solar system, Titan has a significant atmosphere. At the surface, its pressure is more than 1.5 bar (50% higher than Earth 's). It is composed primarily of molecular nitrogen (as is Earth's) with no more than 6% argon and a few percent methane. Interestingly, there are also trace amounts of at least a dozen other organic compounds (i.e.

ethane, hydrogen cyanide, carbon dioxide) and water. The organics are formed as methane, which dominates in Titan's upper atmosphere, is destroyed by sunlight. The result is similar to the smog found over large cities, but much thicker. In many ways, this is similar to the conditions on Earth early in its history when life was first getting started. But it is this thick hazy atmosphere that makes it so hard to see Titan's surface. Titan has no magnetic field and sometimes orbits outside Saturn 's magnetosphere . It is therefore directly exposed to the solar wind . This may ionize and carry away some molecules from the top of the atmosphere. It may also drive some of Titan's peculiar chemistry. At the surface, Titan's temperature is about 94 K (-290 F). At this temperature water ice does not sublimate and thus there is little water vapor in the atmosphere. Nevertheless, there appears to be a lot of chemistry going on; the end result seems to be a lot like a very thick smog. There are scattered variable clouds in Titan's atmosphere in addition to the overall deep haze. These clouds are probably composed of methane, ethane or other simple organics.

Other more complex chemicals in small quantities must be responsible for the orange color as seen from space. Analysis of the Huygens data will tell us a great deal about the details of the atmospheric chemistry. Erosion features Prior to Cassini's arrival, it seemed likely that the clouds would produce a rain of ethane or methane onto the surface perhaps producing an "ocean" up to 1000 meters deep. However, this seems not to be the case at least at the present time. There is little doubt that some active processes are occuring on Titan; there are few if any craters visible indicating that the surface must be very young . But it may be that the "lakes" are more slushy than liquid or that the basins are not filled with liquid at all times. Preliminary results from Huygens indicate that while Titan's rivers and lakes appear dry at the moment, rain may have occurred not long ago. There is clear evidence for "precipitation, erosion, mechanical abrasion and other fluvial activity". In addition, Cassini has found evidence of a peculiar kind of volcano on Titan that may account for some of the unusual features of Titan's atmosphere.

We are beginning to get some understanding of Titan's surface by combining the data from all the sources available. Large ground based observatories operating in the infra-red can see some details as can the Hubble Space Telescope . These show a huge bright "continent" (preliminarily called " Xanadu ") on the hemisphere of Titan that faces forward in its orbit and some darker regions that are suggestive of oceans or lakes. Cassini's much higher resolution infrared images (below right, click for animation) show the same structures in more detail. And the close-ups from Huygens (left) show what appear to be drainage channels and shorelines. These observations also confirm that Titan's rotation is in fact synchronous like most of Saturn's other moons. Cassini's IR camera has detected a strange and as yet unexplained bright spot on Titan's surface. Titan is a difficult object to study. The Cassini instruments are specifically designed to penetrate the haze, its radar mapper can see right thru it and the Huygens images show the surface clearly. But the orbiter images are still frustratingly vague and the Huygens images are few in number and cover only a tiny area.

Analysis of this data will take some time; Titan is a very strange place. More about Titan

Question: Titan is a moon of which planet?
Answer: Saturn