This infrared view of Titan was captured with the Cassini probe wide-angle camera on November 19, 2007 using a spectral filter sensitive to wavelengths of infrared light centered at 939 nanometers. The image presents Titan so that north is up and rotated 21 degrees to the left. From the west to the east, one can notice a portion of Belet, the dark region to the left, the equatorial bright region of Adiri appearing in the middle of the view and on the area which is opposite to Saturn and the dark region of Shangri-La to the east of Adiri. The Huygens probe landing site can be spotted in the north east of Adiri. A previous infrared image of Titan acquired from a roughly similar position had revealed Cirrus-like clouds in the southern hemisphere. This view doesn't show any clear sign of those mid latitude clouds.

Image source: NASA, JPL

This updated infrared map of Titan notably reveals new details of Titan's north polar region. The infrared mosaic was created using views taken by the Cassini spacecraft imaging science subsystem. The images were captured using a filter centered at 938 nanometers in order to pierce Titan's veil and reveal topographic features or albedo variations across the surface of Titan. No topographic shading can be identified due to the scattering of light by Titan's dense atmosphere.
The resolution is not uniform on this equidistant projection. Some parts have been scanned with a high resolution while others have been imaged with a low resolution. The best coverage is near the center and edges of the map ( close to the map scale ) and the worst coverage was obtained on the trailing hemisphere ( centered around 270 degrees west longitude ). The coverage of the north polar region is starting to improve and it will continue to do so over the next couple of years, as Titan approaches vernal equinox in August 2009 and the north pole comes out of shadow. One can spot, already, an irregular dark patch in the northern latitudes, at about 60 degrees north latitude and 330 degrees west longitude. This dark spot appears to be a portion of the largest body of liquid identified so far. That's what suggest the radar images taken in this region.

Image source: NASA, JPL

This mosaic reveals the first radar images of Titan's south polar region. The radar swath was acquired with the Cassini Radar Mapper during the 37th Titan flyby on October 2, 2007. The radar strip is 4,500 kilometers long ( 3,800 miles ) and 150 kilometers ( 93 miles ) wide at the narrowest point. The zoom is 90 by 90 kilometers ( 56 by 56 miles ), centered at 70.5 degrees south and 113.9 degrees west. The insert is in false color. It reveals the presence of lakes, tinted blue, at about 70 degrees south. We know, now, that the north polar region is not the only place covered by hydrocarbon lakes or seas. The south polar region is currently in the summer season. The radar swath also includes broad, steep-sided depressions adjoined to sinuous depressions, interpreted to be empty topographic basins or drained lakes fed by channels, and complex mottled terrain, akin to those at similar latitudes. The future flybys will map closer to the south pole. As a result, other bodies of liquid, lakes or seas are expected to be found.

Image source: NASA, JPL

This Cassini false-color radar view is a mosaic assembled with all the synthetic-aperture radar images to date of Titan's north polar region. The blue and dark features on this image appear to be bodies of liquid methane, ethane or dissolved nitrogen. That's why they are tinted blue or black. A black patch is a lake likely deeper than a blue patch because it absorbs more the radar signal. Let's point out that these artificial colors can be very different from the true color. The radar-bright areas are tinted brown because they are thought to represent solid surface. The terrain in the top center of this composite view is imaged at lower resolution than the remainder of the image.
Roughly 60 percent of Titan's north polar region, above 60 degrees north latitude, is now mapped with radar and around 14 percent of the mapped region is filled with what is believed to be liquid hydrocarbons. This global view of Titan's north pole is reminiscent of terrestrial landscape characteristics such as lakes, seas, bays, islands, peninsulas and rivers. The large dark topographic feature in the upper right center of the mosaic is at least 100,000 square kilometers (40,000 square miles) in area, greater in extent than Lake Superior (82,000 square kilometers or 32,000 square miles), one of Earth's largest lakes. It is not as big as the Black Sea, Earth's largest terrestrial inland sea but it covers a greater fraction of the surface. On the lower right of the mosaic, a portion of what seems to be the first alien sea can be spotted. The VIMS images have recently shown that this portion is probably part of the largest sea ever identied on Titan. Of the 400 observed lakes and seas, 70 percent of their area is taken up by large "seas" greater than 26,000 square kilometers (10,000 square miles).

Image source: NASA, JPL

This ultraviolet image of Titan was captured with the Cassini spacecraft narrow-angle camera on September 2, 2007 using a spectral filter sensitive to wavelengths of ultraviolet light centered at 338 nanometers. The view was acquired at a distance of roughly 1.3 million kilometers or 816,000 miles from Titan and at a Sun-Titan-spacecraft, or phase, angle of 20 degrees.
Two main features appear on this image: first a detached, high-altitude haze layer encircling the hazy and opaque atmosphere and represented by a thin line. The second significant characteristic is a polar hood covering the north pole from high northern latitudes to the north pole. A giant hurricane seems to be engulfing the north polar region,currently in its winter season.

Image source: NASA, JPL

This infrared view of Titan was captured with the Cassini spacecraft wide-angle camera on May 13, 2007. It combines multiple images taken using a combination of spectral filters sensitive to wavelengths of infrared light centered at 939 and 742 nanometers. The rotation axis is inclined 15 degrees to the right and north is up. The area shown is in Titan's trailing hemisphere. One can observe Adiri at the center of the dark portion, a 1,700 kilometer ( 1,050 mile ) wide bright region.The dark regions of Shangri-La and Fensal / Aztlan appear on the eastern part of Adiri and the dark region of Belet is on the west part. One of the noteworthy features in this image is the presence of bright mid-latitude clouds on the lower part of the moon. The cloud bands are long and thin and seem to follow the direction of dominating winds from the west to the east.

Image source: NASA, JPL

This radar view was captured by the Cassini spacecraft during its 31st flyby of Titan ( T30 ) on May 12, 2007. The portion as shown is about 160 kilometers ( 100 miles ) by 270 kilometers ( 170 miles ). The image is centered near 70 degrees north latitude and 310 degrees west longitude.
This radar swath focuses on what is supposed to be the largest body of liquid in Titan's northern region. The observer can appreciate the wealth of landscape features. The dark area which is likely a sea of hydrocarbon molecules, methane and / or ethane, appears completely uniform. It suggests that the sea is relatively deep, probably tens of meters. No depth variations can be spotted. A multitude of islands and peninsulas are unveiled. Some scientists note that the islands on the lower left of the image follow the same direction as the peninsula to their lower right, suggesting that they may be part of a mountain ridgeline that has been flooded. A parallel can be made for instance with Catalina Island off the coast of Southern California. Finally, this landscape seems very similar to terrestrial landscapes from a physical point of view with peninsulas, coastlines, islands, mountains, bays and channels.

Image source: NASA, JPL

This infrared mosaic of Titan was composed on the basis of the T28 flyby in April 2007. It consists of 29 separate frames using a total of 116 images. The views used for the mosaic were acquired on April 11, 2007. The image is centered on the northern part of Titan's trailing hemisphere ( near 31.2 degrees North, 220.7 degrees West ). The bright patch at bottom center near the dark area is the region of Adiri, in the eastern part of the dark area called Belet. The dark area is located at low latitudes. The radar images have shown that the dark areas are dominated by dunes , especially near the equator, formed by dominating winds which blow from the west to the east. Some linear bright landscape features in the dark region tend to indicate that their shape is strongly linked to powerful winds. A dark spot surrounded by a bright material can be identified in the east part of the dark area. It's either the outcome of a meteoritic impact or the outcome of a cryovolcano. The material expelled is likely water ice, carbon dioxyde, ammonia or a substance made of hydrocarbon molecules.
Another striking feature on the mosaic is the presence of dark linear structures coming down from the northern regions. Does it represent drainage channels fed by the big sea recently identified in Titan's north pole? No significant clues for the moment on that point.

Image source: NASA, JPL

This ultraviolet view of Titan's northern latitudes was acquired with the Cassini spacecraft narrow-angle camera using a combination of spectral filters sensitive to wavelengths of polarized ultraviolet light. The image was taken on February 25, 2007 at a distance of approximately 1.3 million kilometers ( 800,000 miles ) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 63 degrees. It was obtained from around 50 degrees above Titan's equatorial plane. The ultraviolet view unveils some atmospheric phenomena in Titan's stratosphere: a multitude of circumpolar bands are clearly visible.They are interpreted as cloud streaks moving around Titan's north pole. Those atmospheric features indicate a superrotation process which reminds us of atmospheric currents on Saturn and Venus. Hence, new details of the moon's stratosphere were obtained by using the ultraviolet spectral filter.

Image source: NASA, JPL

This composite view of Titan's north polar region is part of a movie combining a near-natural color view, an infrared view and radar images.It was obtained by the Cassini spacecraft narrow-angle camera on February 25, 2007, at a distance of about 1.3 million kilometers ( 800,000 miles ) from Titan. The infrared views were captured with a special filter centered at 938 nanometers which allows us to peer through the orange, hazy and opaque atmosphere. The near natural color appearance was generated via images taken at 619, 568 and 440 nanometers. The radar data were obtained in synthetic aperture radar mode.
The latest infrared image of Titan's north polar region reveals a giant dark patch, likely a sea. A portion of this sea has been imaged with the radar mapper. The radar data reinforce the hypothesis that this dark patch is a sea. The lower part of the extent appears uniformly dark which means that it absorbs all the signal like liquid water does on Earth. This body of liquid methane, liquid ethane or liquid hydrocarbons is about the same size as the Caspian Sea on Earth. The second largest body of liquid ( close to the eastern shoreline of the sea ) is roughly the size of Lake Superior.
The wetlands of Titan seem to be located at Titan's high latitudes: Titan's north pole presents a pleiade of lake-like features as well as a sea but the south pole is, probably, not devoid of lakes and seas: the first candidate ever in the quest for lakes was this uniform dark patch in Titan's south pole, about the size of Lake Victoria, with a kidney shape, called "Ontario Lacus". It was surrounded by a multitude of smaller dark patches and accompanied by large cloud formations which had rapidly dissipated. So, much remains to be explored!

Image source: NASA, JPL

This composite image shows, side by side, Lake Superior on the right and what appears to be the largest body of liquid ever found on Titan's north pole ( left part ). The Cassini radar image on the left is a false-color view and the blue extent represents the assumed lake which is at least 100,000 square kilometers ( 39,000 square miles ). That's greater in extent than Lake Superior ( 82,000 square kilometers or 32,000 square miles ), one of Earth's largest lakes. The view on the right is from the SeaWiFS project, NASA's Goddard Space Flight Center, Greenbelt, Md.
The liquid contained in the Titan lake or sea is likely methane, ethane or a mixture of these hydrocarbons. As winter comes to an end and spring is approaching, how will this lake evolve? Will it progressively evaporate? Will it be displaced toward lower latitudes ?

Image source: NASA, JPL

This infrared image of Titan was captured during the flyby of February 25, 2007. It shows another striking feature in Titan's north pole. In the upper part of this view, a dark area with well defined boundaries can be spotted. It is apparently a giant lake or a sea roughly 1,100 kilometers ( 680 miles ) long. Its surface area is slightly smaller than that of Earth's largest lake, the Caspian Sea. Cloud streaks are clearly visible at about 60 degrees north latitude. The bright cirrus-like clouds are located close to the eastern part of the assumed sea. This sea appears largely bigger than "Ontario Lacus", the dark patch identified in Titan's south pole.

Image source: NASA, JPL

This radar image was taken by Cassini's radar instrument in synthetic aperture mode during a near-polar flyby on February 22, 2007. The view is centered at around 3.5 degrees south latitude and 37.3 degrees west longitude in the Fensal / Aztlan region, a landscape feature which looks like the letter "H" in infrared views. North is toward the left. One can clearly see, in this portion, how the prevailing winds shape the landscape: the long, dark and bright streaks are likely sand dunes made up of small hydrocarbon or water ice particles, probably about 250 microns in diameter, similar to sand grains on Earth. The landscape characteristics suggest that prevailing winds blow from the west to the east. The bright patches seem to be topographic obstacles to the winds. The bright patch in the lower part of the image is distorted by the dunes and it deflects the linear movement of the dune formations which flow through and around it. In the upper part of the image, the bright patch appears to stop prevailing winds from acting on the shape of the landscape. It must be composed of hills or elevated terrains.

Image source: NASA, JPL

This radar image was acquired by Cassini's radar instrument in synthetic aperture mode during a near-polar flyby on February 22, 2007. The view is centered at around 79 degrees north and 310 degrees west. North is toward the left. A very large lake, surrounding a big island or peninsula, appears. The island is around 90 kilometers ( 62 miles ) by 150 kilometers ( 93 miles ) across. That's roughly the size of Kodiak Island in Alaska or the Big Island of Hawaii. The portion of the lake above the island, almost 250 km long ( 156 miles ), appears deep since it is uniformly dark and the shoreline is not progressive. The southern part of the lake in the south coast of the big island seems shallow because it is less reflective than the rest of the lake in this radar image.We can find similarities between these topographic features and landscape features on Earth: one can observe, notably, some drainage channels with branching structures, archipelagos as well as a kind of reef. The bright structures are likely elevated terrain, hills or mountains.
The giant lake, in this view, is one of the largest lakes imaged so far. It reinforces the idea that the largest lakes are at the highest latitudes.

Image source: NASA, JPL

This natural color view of the Orange Moon was generated by combining images taken using red, green and blue spectral filters. The three views were acquired by the Cassini orbiter wide-angle camera on January 28, 2007 at a distance of approximately 196,000 kilometers ( 122,000 miles ) from Titan.
The image reveals Titan's high northern latitudes. A striking atmospheric feature can be identified: a banded pattern is encircling the north pole. A dark orange band, relatively wide, can clearly be spotted. Narrower bands are also visible. A parallel can be made with Saturn's atmospheric structure. This phenomenon is what scientists expect to see in the Titanian stratosphere, where the atmosphere is superrotating, or moving around the moon faster than the moon itself rotates. On that point, we find similarities between the Titan atmosphere and the Venus atmosphere.

Image source: NASA, JPL

This radar mosaic is composed of two images captured by the Cassini radar mapper on two flybys. The lower part of the swath was obtained during the flyby of October 26, 2005, while the upper part of the image was acquired during the flyby of January 13, 2007. Both images were taken in synthetic aperture mode. The area is about 570 kilometers ( 354 miles ) wide and 390 kilometers ( 240 kilometers ) high. North is toward the top. The dark circular feature on the lower left of the image, called Ganesa Macula, is interpreted as a cryovolcano or ice volcano. A bright patch in the middle of Ganesa Macula can be spotted. It has connections with bright lines or streaks that "feed" the terrain surrounding the cryovolcano. The volcanic fluid or cryolava seems to run mostly eastward since the bright material is much more concentrated in the east part of the assumed volcano. It is likely closely linked to dominating winds which blow from the west to the east. Bright rounded landscape features, also interpreted as cryovolcanic flows, are observed towards the top and the right of the mosaic.

Image source: NASA, JPL

This radar image was acquired by Cassini's radar mapper during the Titan flyby of January 13, 2007. It was taken in synthetic aperture mode. The image is around 240 kilometers ( 150 miles ) wide by 140 kilometers ( 90 miles ) high and it is centered at about 26.5 degrees north and 9 degrees west. North is toward the top left corner of the strip. A semi-circular dark patch can be spotted. It appears to be a part of an impact crater, roughly 180 kilometers ( 110 miles ) wide. Very few impact craters have been identified on Titan which means that the surface is relatively young. Cryovolcanoes or rainfall must play a key role in resurfacing Titan's landscape. The bright material surrounding the round feature seems to be the crater's ejecta blanket. It is probably topographically higher than the surrounding plains. Some scientists speculate it might be composed of a mixture of water ice and ammonia. The inner part of the crater is very dark meaning that it is made of smooth deposits( hydrocarbon deposits...). The possibility that it is composed of liquid methane or ethane is not ruled out.

Image source: NASA, JPL

This composite infrared image of Titan's north pole was acquired by the Cassini's visual and infrared mapping spectrometer during the flyby of December 29, 2006. A giant circular cloud formation about half the size of the United States can be spotted. The mammoth cloud covers the north pole down to a latitude of 62 degrees north and at all observed longitudes. It was imaged at a distance of 90,000 kilometers ( 54,000 miles ). The image was color-coded, with blue, green and red at 2 microns, 2.7 microns, and 5 microns, respectively. The goal was to observe the limb of the moon. The atmospheric circulation models of Titan predicted the cloud cover in the north pole. The cloud is probably closely linked to the lakes observed in the north polar region by the Cassini's radar instrument. Is it the result of evaporating methane or ethane lakes? Is it raining methane or ethane? Are there flashes of lightning and thunderstorms?

Image source: NASA, JPL

This radar image was captured by the Cassini's radar mapper in synthetic aperture mode during the Titan flyby of January 13, 2007. The image is approximately 160 kilometers ( 100 miles ) long by 150 kilometers ( 90 miles ) wide. North is toward the top left corner of the image.
The dark and bright straight lines also called cat scratches appear to be dunes drawn by the wind. The winds on Titan tend to blow from the west to the east. The assumed dunes which are a common landform in the equatorial region are probably composed of organic material. Some scientists advance that the bright strips are not made of the same material as the dark streaks. The bright patch at the lower left of the image seems to be an elevated terrain. The circular features surrounded by a bright material, at the top center of the image, may be craters slowly being buried by the dunes. It gives an idea about the process and dynamism of dune formation.

Image source: NASA, JPL

This incomplete infrared map of Titan consists of images taken using a filter centered at 938 nanometers. It was produced using data acquired by the Cassini spacecraft Imaging Science Subsystem ( ISS ). The darker the area on this map, the less reflective it is. The brighter the area, the more reflective it is. Any lake or sea is expected to have a low albedo and to appear dark on this map. No topographic shading is visible in these images because light is scattered by Titan's dense atmosphere. The map is an equidistant projection which preserves distances on the globe, with some distorsion of area and direction. The resolution is low in some areas like Adiri, Belet, Senkyo or towards the north polar regions while it is relatively high in the regions of Shangri-La, Xanadu, Fensal and Aztlan. The worst coverage is on the trailing hemisphere centered around 270 degrees west longitude.
Northern Belet, Adiri and Dilmun will be imaged in February 2007. So, their coverage should improve significantly. Imaging coverage in the northern polar region, currently blank on this map, will ameliorate over the next few years, as Titan approaches vernal equinox in August 2009.
The named features are designated by the International Astronomical Union. A facula on Titan is a bright spot and a macula is a dark spot. It will be interesting to see how Titan's north polar region appears in infrared images in order to make a parallel with radar images of the north polar region which revealed lakes and drainage channels. Titan's south pole is also intriguing with this large dark patch called "Ontario Lacus" assumed to be a giant lake. Radar images of this area should make the interpretation more relevant.

Image source: NASA, JPL

This radar strip was taken on July 22, 2006 by Cassini's radar instrument in synthetic aperture mode. The swath starts at the left ( 20 degrees north by 142 degrees west ). It follows a path toward the north and ends at 13 degrees north by 347 degrees west. One can clearly observe lakes north of 70 degrees latitude around the north pole.At the far left, a dark circular feature about 75 kilometers ( 47 miles ) in diameter, surrounded by a bright material, appears. It's probably an impact crater but the hypothesis of a volcanic caldera can't be ruled out. Up to 70 degrees north, the contrast between dark and bright areas is not pronounced. Other less distinct round shapes can be spotted. Some irregular features which seem to have been carved by a liquid can be identified. They may be dried lakes. By continuing to the right, one encounters a contrasted terrain with bright patches and dark meandering channels or valleys. It's likely that the bright patches are mountains, hills or plateaus. At around 70 degrees north, the dark lakes begin to appear. The lakes seem to be deeper close to the pole because they are darker. Some lakes are connected to dark channels, likely drainage channels. Some lakes have clear rims and other lakes have broad rims which tends to indicate that they are not completely filled with the liquid or that they are drying up. The enigmatic liquid is probably methane or ethane. But there is a slight chance that the lakes are filled with nitrogen. We leave the north pole and continue our journey toward the south. Apparently, some dry lakes start to appear. Irregular and complex terrain with mountains, hills or canyons begins to dominate. At the extreme right end, the famous cat scratches appear. The dark grooves are straight, drawn by the wind which blows from the west to the east.

Image source: NASA, JPL

Both images showing the same area were captured by the Cassini spacecraft radar mapper on two different Titan flybys on December 11, 2006 ( T21 left ) and October 29, 2005 ( T8 right ). The images were taken in synthetic aperture mode. North is toward the top of both images. Each radar view is approximately 400 kilometers ( 250 miles ) long by 275 kilometers ( 170 miles ) wide. The images reveal a field of dunes located near 9.4 degrees south latitude by 290 degrees west longitude. Apparently, the dunes are engendered by a wind blowing in an eastward direction. The bright circular feature on the right part of the image seems to be an elevated terrain since it deflects the direction of the dunes toward the north. In other words, it acts as an obstacle. What kind of obstacle? Probably a mountain, hills or cliffs. The radar images have a different appearance because the radar instrument illuminated the dunes from different directions. Imagine that the radar signal comes from the left in the left image and from the top in the right image. The dunes are more clearly defined in the right image as their faces are caught by the illumination. It is surprising to observe a systematic contrast between the dunes in both views. As a result, it is tempting to say that the materials making up the dark and light stripes are likely different. The way the dunes reflect radar waves gives us clues about the nature of their compounds.

Image source: NASA, JPL

This modified radar image, tinted in false colours is based on the radar image in synthetic aperture mode taken during the Titan flyby of July 22, 2006. The strip of radar imagery is foreshortened to simulate an oblique view of the highest latitude region, seen from a point to its west. The image is centered near 80 degrees north, 35 degrees west and is around 140 kilometers ( 84 miles ) across. This image was published in the journal Nature on January 4, 2007 and appeared on the journal's cover. It reveals striking clues that the region is filled with large bodies of liquid, probably liquid methane or liquid ethane. Intensity in this colorized view is proportional to how much radar brightness is returned , or more specifically , the logarithm of the radar backscatter cross-section. The lakes, darker than the surrounding terrain, are emphasized here by tinting regions of low backscatter in blue. Radar-brighter regions are shown in tan.

Image Source: NASA, JPL, Nature