A large ringed feature on Titan located at 5.0N, 341.2W has been named Paxsi. For more information, see the feature page and the image of Titan in the Gazetteer of Planetary Nomenclature.
This graphic, constructed from data obtained by NASA's Cassini spacecraft, shows the percentage of cloud coverage across the surface of Saturn's moon Titan. The color scale from black to yellow signifies no cloud coverage to complete cloud coverage, over a period spanning July 2004 to April 2010.
Equinox, when the Sun shone directly over the equator, occurred in August 2009. It brought a changing of the seasons, as Titan moved out of southern summer into northern spring.
During winter in the northern hemisphere, northern polar clouds of ethane formed in Titan's troposphere, the lowest part of the atmosphere, from a constant influx of ethane and aerosols from a higher part of the atmosphere known as the stratosphere. In the southern hemisphere, atmospheric gases enriched with methane welled up from the surface to produce mid- and high-latitude clouds.
The amount and location of cloud coverage on Titan provide clues to seasonal changes on the moon. During southern summer, Cassini scientists saw a thick vortex of clouds at Titan's north pole, and a thinner patch at the south pole. Wispier mid-latitude clouds sometimes appeared in the southern temperate zones. Scientists are closely watching to see if this picture will change as northern summer approaches. They will observe whether the south polar clouds grow as the north polar clouds dissipate, and whether northern temperate clouds appear as those in the south disappear.
The data for this graphic came from Cassini's visual and infrared mapping spectrometer.
This pair of false-color images, made from data obtained by NASA's Cassini spacecraft, shows clouds covering parts of Saturn's moon Titan in yellow. Based on the way near-infrared channels of light were color-coded, cloud cover appears yellow, while Titan's hazy atmosphere appears magenta. The images show cloud cover dissolving from Titan's north polar region between May 12, 2008 (left), and December 12, 2009 (right). The clouds in the second image appear around 40 degrees south latitude, still active late after Titan's equinox.
Cassini's first observations of clouds near this latitude occurred during summer in the southern hemisphere. Equinox, when the Sun shone directly over the equator, occurred in August 2009. It brought a changing of the seasons, as Titan moved out of southern summer into northern spring.
For the past six years, Cassini has observed clouds clustered in three distinct latitude regions of Titan: large clouds at the north pole, patchy clouds at the south pole and a narrow belt around 40 degrees south. Now scientists are seeing evidence of seasonal circulation turnover at Titan. Clouds at the south pole disappeared just before equinox and the clouds in the north are thinning out. This activity agrees with models that predict cloud activity reversing from one hemisphere to another.
During winter in the northern hemisphere, northern polar clouds of ethane formed in Titan's troposphere, the lowest part of the atmosphere, from a constant influx of ethane and aerosols from a higher part of the atmosphere known as the stratosphere. In the southern hemisphere, atmospheric gases enriched with methane welled up from the surface to produce mid- and high-latitude clouds.
The data for the images was detected by Cassini's visual and infrared mapping spectrometer in near-infrared wavelengths. Scientists focused on three wavelengths of infrared radiation that were particularly good for observing cloud signatures and assigned them red, green and blue channels. Emissions in the 2 micron wavelength of light, colored red, detect the Titan surface. Emissions in the 2.11 micron wavelength, colored green, detect the lowest part of the Titan atmosphere, or troposphere. Emissions at the 2.21 micron wavelength, colored blue, detect the hazy stratosphere, a higher part of the atmosphere. The clouds appear yellowish because they lit up the channels designated red and green, but not the blue channel.
The Cassini spacecraft looks between Saturn's A and B rings to spy structure in the Cassini Division.
The Cassini Division, occupying the middle and left of the image, contains five dim bands of ring material, but not all of the division is shown in this image. The B ring is on the right of the image. The Huygens Gap is the widest black swath near the middle of the image. See PIA11142, PIA08901 and PIA08330 to learn more. This view looks toward the northern, sunlit side of the rings from about 3 degrees above the ringplane.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on September 3, 2010. The view was obtained at a distance of approximately 443,000 kilometers (275,000 miles) from Saturn. Image scale is 2 kilometers (1 mile) per pixel.
This set of enhanced-color maps made from data obtained by NASA's Cassini spacecraft show Saturn's moons Mimas, Enceladus, Tethys, Dione and Rhea. The global maps show the colorful splotches and bands on the icy moons' surfaces that scientists believe came from bombardments large and small.
Icy material sprayed by Enceladus, which makes up the misty E ring around Saturn, appears to leave a brighter, blue signature. The pattern of bluish material on Enceladus, for example, indicates that the moon is covered by the fallback of its own "breath."
Enceladean spray also appears to splatter the parts of Tethys, Dione and Rhea that run into the spray head-on in their orbits around Saturn. But scientists are still puzzling over why the Enceladean frost on the leading hemisphere of these moons bears a coral-colored, rather than bluish, tint.
On Tethys, Dione and Rhea, darker, rust-colored reddish hues paint the entire trailing hemisphere, or the side that faces backward in the orbit around Saturn. The reddish hues are thought to be caused by tiny particle strikes from circulating plasma, a gas-like state of matter so hot that atoms split into an ion and an electron, in Saturn's magnetic environment. Tiny, iron-rich "nanoparticles" may also be involved, based on earlier analyses by the Cassini visual and infrared mapping spectrometer team.
Mimas is touched by the tint of Enceladean spray, but it appears on the trailing side of Mimas. This probably occurs because it orbits inside the path of Enceladus, or closer to Saturn, than Tethys, Dione and Rhea.
Mimas and Tethys also sport a dark, bluish band. The bands match patterns one might expect if the surface were being irradiated by high-energy electrons that drift in a direction opposite to the flow of plasma in the magnetic bubble around Saturn. Scientists are still figuring out exactly what is happening on Mimas, but the electrons appear to be zapping the surface in a way that matches the Pac-Man pattern detected by Cassini's composite infrared spectrometer.
On Rhea, a unique chain of bluish splotches appears where fresh, bluish ice has been exposed on older crater rims. Cassini imaging scientists recently reported that they did not see evidence in Cassini images of a ring around Rhea. However, scientists analyzing these new enhanced-color maps suggest the crash of orbiting material, perhaps a ring, to the surface of Rhea in the not too distant past, could explain the bluish splotches.
These new maps were made by processing raw images obtained by Cassini's imaging cameras from 2004 to 2009. Scientists analyzed frames shot through visible-light, ultraviolet and infrared filters. The processing enhanced our views of these moons beyond what could be seen by the human eye.
The maps are in a simple cylindrical projection from 90 degrees south latitude (bottom) to 90 degrees north latitude (top). From left to right, they cover 360 degrees west longitude to minus 2 degrees west longitude. The leading hemisphere appears on the right side of each map and trailing hemisphere appears on the left.
These three views of Saturn's moon Rhea were made from data obtained by NASA's Cassini spacecraft, enhanced to show colorful splotches and bands on the icy moon's surface. Scientists believe the reddish and bluish tints came from bombardments large and small.
Icy material sprayed by the moon Enceladus hits Rhea head-on in its orbit around Saturn and leaves a coral-colored tint. Darker, rust-colored reddish hues paint the trailing hemisphere, or the side that faces backward in the moon's orbit around Saturn. The reddish hues are thought to be caused by tiny particle strikes from circulating plasma, a gas-like state of matter so hot that atoms split into an ion and an electron, in Saturn's magnetic environment. Tiny, iron-rich "nanoparticles" may also be involved, based on earlier analyses by the Cassini visual and infrared mapping spectrometer team.
Rhea sports a chain of bluish splotches along the equator that appear where fresh, bluish ice has been exposed on older crater rims. Cassini imaging scientists recently reported that they did not see evidence in Cassini images of a ring around Rhea. However, scientists analyzing these enhanced-color views suggest the bluish material could have been exposed by the crash of orbiting material -- perhaps a ring -- to the surface of Rhea in the not too distant past.
These images were made by processing raw images obtained by Cassini's imaging cameras in November 2005. Scientists analyzed frames shot through visible-light, ultraviolet and infrared filters. The processing enhanced our views of these moons beyond what could be seen by the human eye.
The image on the left shows a composite image made from data in the infrared, green and ultraviolet filters. The middle view shows an image made from data analyzing the ratio of infrared to green wavelengths, indicating the relative redness of the features. The brighter the feature is in this middle view, the redder it is. The image on the right shows data analyzing the ratio of infrared to ultraviolet wavelengths. The darker the feature is, the bluer the tint
In each of these images, the trailing hemisphere is on the left side and leading hemisphere is on the right side. They are centered near 145 degrees west longitude, about 35 degrees east of the boundary between the leading and trailing hemispheres. The bright crater Inktomi can be seen near the center of the images on the left and right, but was more difficult to see in the middle image because of there is less contrast in the infrared/ultraviolet ratio.
A darkly defined Rhea passes before the fuzzy orb of Titan in this Cassini view of Saturn's two largest moons.
Rhea is closer to the spacecraft in this view. See PIA09895 to learn more about Rhea. See PIA08137 to learn more about Titan's atmosphere.
Lit terrain seen here is on the Saturn-facing sides of Rhea (1,528 kilometers, or 949 miles across) and Titan (5,150 kilometers, or 3,200 miles across).
The image was taken in visible blue light with the Cassini spacecraft narrow-angle camera on November 19, 2009. The view was acquired at a distance of approximately 1.1 million kilometers (684,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 118 degrees. The view was acquired at a distance of approximately 2.3 million kilometers (1.4 million miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 118 degrees. Image scale is 7 kilometers (4 miles) per pixel on Rhea and 14 kilometers (9 miles) on Titan.
Swinging by Saturn's small moon Epimetheus, Cassini snapped this shot during the spacecraft's April 7, 2010, flyby.
See PIA09813 and PIA06226 for even closer views from earlier flybys. Lit terrain seen here is on the Saturn-facing side of Epimetheus (113 kilometers, or 70 miles across). North on Epimetheus is up and rotated 27 degrees to the left.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was acquired at a distance of approximately 87,000 kilometers (54,000 miles) from Epimetheus and at a Sun-Epimetheus-spacecraft, or phase, angle of 69 degrees. Image scale is 519 meters (1,703 feet) per pixel.
This enhanced-color view of Saturn's moon Mimas was made from images obtained by NASA's Cassini spacecraft. It highlights the bluish band around the icy moon's equator. The view shows the hemisphere that faces forward in Mimas' orbit around Saturn. The large round gouge on the surface is Herschel Crater.
This composite image was made by processing raw images obtained by Cassini's imaging cameras from 2004 to 2009. Scientists analyzed frames shot through visible-light, ultraviolet and infrared filters. The processing enhanced our views of these moons beyond what could be seen by the human eye.
The dark, bluish band around Mimas matches patterns one might expect if the surface were being irradiated by high-energy electrons that drift in a direction opposite to the flow of plasma in the magnetic bubble around Saturn. Scientists are still figuring out exactly what is happening, but the electrons appear to be zapping the Mimas surface in a way that matches the Pac-Man thermal pattern detected by Cassini's composite infrared spectrometer early in 2010.
Although traveling at great speed, the Cassini spacecraft managed to capture this close view of Saturn's small moon Helene during a flyby on March 3, 2010.
Saturn's atmosphere makes up the background of this composition. See PIA12653 for another image taken during this closest flyby of Helene.
This view looks toward the anti-Saturn side of Helene (33 kilometers, or 21 miles across). North on Helene is up and rotated 44 degrees to the right.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was obtained at a distance of approximately 19,000 kilometers (12,000 miles) from Helene and at a Sun-Helene-spacecraft, or phase, angle of 25 degrees. Image scale is 113 meters (371 feet) per pixel.
