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Ring-Grazing and Grand Finale Orbits with Titan

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Cassini Grand Finale: Navigating the Gap

Illustration showing close approach to Saturn's atmosphere.

March 24, 2017

This diagram created by Cassini mission planners illustrates the close approaches of the spacecraft during its Grand Finale orbits between Saturn's innermost (D) ring and the giant planet's atmosphere.

Here is a simplified version:

Illustration of Cassini's final orbits between the innermost ring and Saturn's atmosphere. — Mission planners call Cassini's final orbits "proximal" because the spacecraft is in very close proximity to Saturn.

Credit

NASA / Jet Propulsion Laboratory - Caltech / Erick Sturm

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During its final months, the Cassini spacecraft will climb repeatedly high above the planet’s north pole and then dive between the planet and the innermost edge of its dazzling rings.

Illustration showing Cassini's final orbits.

Orbit Plot: Cassini Grand Finale (Artist's Concept)

Epimetheus floats in the distance below center, showing only the barest hint of its irregular shape. Pandora hides herself in the ringplane, near upper right, appearing as little more than a bump. This view is from just above the ringplane and shows features on the unlit side of Saturn's rings. Epimetheus (116 kilometers, or 72 miles across) and Pandora (84 kilometers, or 52 miles across) hug the outer reaches of Saturn's main rings. Pandora orbits just outside the F ring, and Epimetheus jockeys for position with Janus, 10,000 kilometers beyond. Janus and Epimetheus recently swapped positions, and Janus will remain the innermost of the pair until 2010, when they will swap positions again. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 29, 2006, at a distance of approximately 3.3 million kilometers (2 million miles) from Saturn. The image scale is approximately 20 kilometers (12 miles) per pixel at the distance of Saturn. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit:NASA/JPL/Space Science Institute

The unlit side of Saturn's rings, Epimetheus and Pandora

Ring-Hugging Moons

Saturn's rings cast wide shadows on the planet, and the shadow of a moon also graces the gas giant in this scene from the Cassini spacecraft. The moon Enceladus is not shown in this view, but it does cast a small, elongated shadow on the planet near the bottom of this view. The moon Mimas (246 miles, or 396 kilometers across) is visible as a bright dot on the far right of the image in the ring plane. This view looks toward the southern, unilluminated side of the rings from about 2 degrees below the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on Jan. 14, 2012 using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers. The view was acquired at a distance of approximately 1.7 million miles (2.8 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 51 degrees. Image scale is 105 miles (170 kilometers) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov or http://www.nasa.gov/cassini . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL-Caltech/Space Science Institute

Shadows on a Giant

Artist's concept of Cassini orbiter crossing Saturn's ring plane.

Illustration of spacecraft at Saturn.

Crossing the Ring Plane

+ View Full-Res This image was obtained by Cassini's radar instrument during a flyby on Oct. 9,2006. The radar antenna was pointing toward Titan at an altitude of 980 kilometers 609 miles) during the closest approach. For more information about the flyby, please see the T-19 Flyby Page. The image has been processed with a resolution of 128 pixels/deg. The image is available within the NASA Planetary Data System. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries. Credit: NASA/JPL-Caltech

Titan seen by Cassini radar

Titan Radar Swath (T-19 Flyby - Oct. 9, 2006)

Off the shoulder of giant Saturn, a bright pinpoint marks the location of the ring moon Atlas (image center). Shadows cast by the C ring adorn the planet at upper right. The thin boundary of Saturn's high haze layer can be seen immediately to the left of the planet's limb, near center. This view looks toward the unilluminated side of the rings from less than a degree above the ringplane. Atlas is 32 kilometers (20 miles) across. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 17, 2007 at a distance of approximately 2.2 million kilometers (1.3 million miles) from Saturn. Image scale is about 13 kilometers (8 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute

Saturn, its rings and the moon Atlas

Sojourn at Saturn

This recording is a laboratory reconstruction of the sounds heard by a microphone on the Huygens probe as it descended to Titan's surface. Several sounds, taken at different times during the descent, are combined and give a realistic reproduction of what a traveler on board Huygens would have heard during one minute of the descent through Titan's atmosphere.

Titan, Here We Come

Titan, Here We Come

Saturn's B ring is spread out in all its glory in this image from Cassini. Scientists are trying to better understand the origin and nature of the various structures seen in the B ring. Saturn's B ring is the densest and most massive of all the rings. The C ring is also visible inside the B ring and the A ring puts on an appearance beyond the Cassini Division near the top and bottom of the image. This view looks toward the sunlit side of the rings from about 7 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on July 22, 2012. The view was obtained at a distance of approximately 201,000 miles (324,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 134 degrees. Image scale is 10 miles (16 kilometers) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL-Caltech/Space Science Institute

Saturn's B ring is spread out in all its glory in this image from Cassini.

The Cassini spacecraft catches a glimpse of features that reveal important clues about processes occurring in Titan's atmosphere. The north polar stratosphere exhibits a banded appearance, as fast-moving clouds whirl around the giant moon. The moon's halo -- its detached, high-altitude global haze layer -- is faintly visible here as well. Planet-sized Titan is 5,150 kilometers (3,200 miles) across. The image was taken with the Cassini spacecraft narrow-angle camera using a combination of spectral filters sensitive to wavelengths of polarized ultraviolet light. The image was obtained on May 15, 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 25 degrees. Image scale is 15 kilometers (10 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit HYPERLINK "http://saturn.jpl.nasa.gov" http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at HYPERLINK "http://ciclops.org" http://ciclops.org . Credit: NASA/JPL/Space Science Institute

High Altitude Hints

Possible variations in chemical composition from one part of Saturn's ring system to another are visible in this Voyager 2 picture as subtle color variations that can be recorded with special computer-processing techniques. This highly enhanced color view was assembled from clear, orange and ultraviolet frames obtained August 17, 1981 from a distance of 8.9 million kilometers (5.5 million miles). In addition to the previously known blue color of the C-ring and the Cassini Division, the picture shows additional color differences between the inner B-ring and outer region (where the spokes form) and between these and the A-ring. For a high resolution image, click here.

Ring Color Variations

Ring Color Variations

+ Annotated Version This image from NASA's Cassini spacecraft shows an ancient southern sea that used to sprawl out near the south pole of Saturn's moon Titan. In an annotated version, the red outline traces the ancient shoreline. Within this basin is the largest present-day lake in Titan's southern hemisphere, Ontario Lacus. Ontario Lacus appears black, indicating it is filled with liquid. This image was obtained by Cassini's radar instrument on July 2009 and January 2010. Several images have been stitched together. By analyzing these images, scientists estimate the ancient sea was possibly as large as 300 by 170 miles (475 by 280 kilometers) across and likely less than a few hundred feet (meters) deep. Ontario Lacus is about 80 by 235 kilometers across, and probably at least 30 feet (10 meters) deep at its center. Seas may have covered large parts of the southern hemisphere less than 50,000 years ago. Titan, Saturn’s largest moon, is the only place besides Earth in our solar system that hosts large open bodies of liquid. At the cold temperatures of Titan, about minus 290 degrees Fahrenheit (94 kelvins), that liquid is not water, but methane and ethane. Over one hundred lakes and three seas are seen at the north pole of Titan, while the south pole only has a few small lakes. Scientists have suggested that cycles analogous to Croll-Milankovich cycles on Earth cause long-term cyclic transfer of liquid hydrocarbons from pole to pole, with the north pole now containing the bulk of the liquids. Less than 50,000 years ago, the cycle would have been reversed, suggesting that the south polar region should contain remnants of southern seas. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, DC. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries. For more information about the Cassini-Huygens mission, visit http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov/ . Credit: NASA/JPL-Caltech/ASI/Proxemy Research

This image from NASA's Cassini spacecraft shows an ancient southern sea that used to sprawl out near the south pole of Saturn's moon Titan.

Outline of an Ancient Sea on Titan -- Unannotated

Saturn's F ring displays magnificent structure following the passage of Prometheus. Atlas (32 kilometers, or 20 miles across) is seen between the A and F rings, above center. This view looks toward the unilluminated side of the rings from about 28 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 23, 2008. The view was acquired at a distance of approximately 1.7 million kilometers (1.1 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 41 degrees. Image scale is 10 kilometers (6 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute

Saturn's F ring

Trailing Prometheus

Streamers and Swirls November 8, 2004 Full-Res: PIA06515 This image from Cassini shows details in the alternating light and dark bands in Saturn's southern hemisphere. Visible details in this image are a dark, curved ribbon near upper left, and an elliptical dark spot with attached streamers above and left of center. The image was taken with the Cassini spacecraft narrow angle camera on Sept. 25, 2004, at a distance of 7.7 million kilometers (4.8 million miles) from Saturn through a filter sensitive to wavelengths of infrared light centered at 727 nanometers. The image scale is 46 kilometers (29 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Image Credit: NASA/JPL/Space Science Institute

Streamers and Swirls

Streamers and Swirls

The shadow of the moon Janus dwarfs the shadow of Daphnis on Saturn's A ring in this image taken as the planet approached its August 2009 equinox. Daphnis (8 kilometers, or 5 miles across) orbits in the A ring's Keeler Gap and, along with the moon's attending edge waves, can be seen casting a short shadow in the top left quadrant of the image. Equinox has exposed shadows cast by these edge waves, or vertical structures of ring material created by Daphnis' gravity (see Wave Shadows in Motion). Janus (179 kilometers, or 111 miles across) is not pictured here, but the moon's shadow stretches across the A ring from the center of the image to near the Encke Gap on the left of the image. The Cassini Division appears bright on the right of the image. The novel illumination geometry created around the time of Saturn's August 2009 equinox allows out-of-plane structures and moons orbiting in or near the plane of Saturn's equatorial rings to cast shadows onto the rings. These scenes are possible only during the few months before and after Saturn's equinox, which occurs only once in about 15 Earth years. To learn more about this special time and to see movies of moons' shadows moving across the rings, see Moon Shadow in Motion and Weaving a Shadow. This view looks toward the unilluminated side of the rings from about 27 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on July 11, 2009. The view was obtained at a distance of approximately 491,000 kilometers (305,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 26 degrees. Image scale is 26 kilometers (16 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute

The shadow of the moon Janus dwarfs the shadow of Daphnis on Saturn's A ring

Long Shadow, Short Shadow

An artist's concept of what it might look like from the surface of Saturn's giant moon Titan.

Color illustration showing lakes on the surface of Titan.

Moon under Saturn July 14, 2004 Full-Res: PIA05416 Saturn's captivating cloud bands display a number of interesting features in this narrow angle camera image taken by the Cassini spacecraft on May 20, 2004. On close inspection, the sub-equatorial bands at around 20 degrees south latitude have a braided rope-like appearance. Also noteworthy are swirls and vortices around 60 degrees south latitude. The moon Mimas (398 kilometers, or 247 miles across) is visible just below and to the right of Saturn's South Pole. The image was taken when Cassini was 22 million kilometers (13.7 million miles) from Saturn through a filter centered at 727 nanometers. The image scale is 131 kilometers (81 miles) per pixel. Contrast in the image was enhanced to aid visibility. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Credit: NASA/JPL/Space Science Institute

Moon under Saturn

Moon under Saturn

A shepherd moon can do more to define ring structures than just keep the flock of particles in line, as Cassini spacecraft images such as this have shown. Prometheus (102 kilometers, or 63 miles across) is seen here with two long streamers of material that it has pulled out of the F ring. When Prometheus comes close to the F ring in its orbit, the moon's gravity tugs on the ring particles. The disturbed particles, now pulled into orbits slightly closer to Saturn and therefore faster, shear out during successive orbits, creating the long and delicate streamers seen here. This view looks toward the unlit side of the rings from about 31 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 29, 2006 at a distance of approximately 1.7 million kilometers (1 million miles) from Prometheus and at a Sun-Prometheus-spacecraft, or phase, angle of 160 degrees. Image scale is 10 kilometers (6 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The Cassini imaging team homepage is at http://ciclops.org. Credit: NASA/JPL/Space Science Institute

Saturn's rings and Prometheus

The Hand of Prometheus

This graphic and animation depicts a cross-section of the Saturnian moon Titan.

An Ocean Runs Through It

An Ocean Runs Through It

Titan Flyby Animation September 25, 2004 Full-Res: PIA06119 QuickTime Movie This computer animation shows the planned observations by Cassini spanning roughly a two-day period surrounding its first very close approach to Titan on Tuesday, Oct. 26, at 8:30 a.m. Pacific Daylight Time, at Saturn, or 9:50 PDT, Earth-received time. The animation extends from Oct. 25, 10:20 a.m. PDT, to Oct. 26, 7:20 p.m. PDT. Red indicates observations to be taken in infrared, white in visible light, and purple in utlraviolet. Green indicates radar observations. The name of the instrument team that has designed the observation - imaging science subsystem, visual and infrared spectrometer, composite infrared spectrometer, ultraviolet imaging spectrograph, radar -- is shown. The globe of Titan is covered with the map of imaging data shown in PIA 06116. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Image Credit: NASA/JPL/Space Science Institute

Titan Flyby Animation

Titan Flyby Animation

A soft collision between Prometheus and the F ring created the dark channel goring the ring in the bottom of this image. And, like a silhouette sneaking away from the scene, the lit limb of Prometheus (86 kilometers, or 53 miles across) is visible near the top of the image. This image is a mosaic of two images taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 2, 2009. This view looks toward the sunlit side of the rings from about 24 degrees below the ringplane. The view was acquired at a distance of approximately 567,000 kilometers (352,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 148 degrees. Image scale is 3 kilometers (2 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute

Prometheus and the F ring

F Ring Fender Bender

Swirling cloud bands, delicate ring shadows and icy moons make the Saturn system a place of supreme natural beauty. Even Cassini's remarkable images can only provide the slightest sense of the experience of actually being there. Tethys (at the right, 1,071 kilometers, or 665 miles across) and Mimas (near the center, 397 kilometers, or 247 miles across) are captured here against the planet's turbulent atmosphere. Although the rings are only a thin strip from this angle, one can see the structure of the entire main ring system in its shadow on the planet - from the C ring at the bottom to the faint specter of the F ring at the top. The image was taken in visible violet light with the Cassini spacecraft wide-angle camera on July 16, 2005, at a distance of approximately 1.2 million kilometers (700,000 miles) from Saturn. The image scale is 66 kilometers (41 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute

Tethys (at the right) and Mimas (near the center) are captured in this imag against Saturn's turbulent atmosphere.

Saturn's moon Tethys casts a wide shadow over the planet's F and A rings. Tethys itself is not visible in this image. As Saturn approaches its August 2009 equinox, the planet's moons cast shadows onto the rings. To learn more about this special time and to see a movie of a moon's shadow moving across the rings, see Moon Shadow in Motion. This view looks toward the sunlit side of the rings from about 36 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on April 21, 2009. The view was obtained at a distance of approximately 1.1 million kilometers (684,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 142 degrees. Image scale is 63 kilometers (39 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute

Tethys' shadow over Saturn's rings

In this synthetic aperture radar image obtained by NASA's Cassini spacecraft, two generally similar features, upper center and lower right, appear to be low mountains with grooves running roughly in the up-down direction. A set of straight lines are also visible at lower left. But what made the grooves? Grooves can result from forces that originate from within a planet, including forces that pull the crust of a planet apart and cracks produced by melt intruding into the crust. They can come from external forces like wind or rainfall, which produces river channels that can cut down through layers of rock. All of these produce grooves on Earth's surface, and may also be at work on Titan. Another intriguing thing about this image is that in this image the "light" (actually the radar illumination) comes from the top. With this kind of illumination, the upper side of these mountains should be bright because they face the illumination, but the left side of the upper-center feature and the right side of the lower feature are bright. The brightness indicates that there is a different material in these areas, and the grooves exist in both dark and light materials. The Titan Radar Mapper acquired this image at 41 degrees north latitude and 213 degrees west longitude on Dec. 28, 2009. The image measures 250 kilometers (160 miles) high and 285 kilometers (180 miles) wide, with resolution of about 350 meters (1,100 feet) per pixel. North is left, and the image is illuminated from the top. Incidence angle varies from 11 to 25 degrees. Two dark horizontal lines that run across the middle of the image show the joints between individual radar beams and are not features on the Titan surface. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov/ and http://www.nasa.gov/cassini. Credit: NASA/JPL

Radar image of Titan

New Wrinkles on Titan

This figure illustrates the unexpected and bizarre pattern of daytime temperatures found on Saturn's small inner moon Mimas (396 kilometers, or 246 miles, in diameter).

This figure illustrates the bizarre pattern of daytime temperatures found on Mimas

Bizarre Temperatures on Mimas

While the curtain-like auroras we see at Earth are green at the bottom and red at the top, NASA's Cassini spacecraft has shown us similar curtain-like auroras at Saturn that are red at the bottom and purple at the top. This is how the auroras would look to the human eye.

Saturn's aurora

Saturn's Colorful Aurora (annotated)

The Journey

Cassini Timeline

Timeline

Dive deep into the story of the Cassini-Huygens mission to explore the Saturnian system.

The Spacecraft

Find out how the Cassini orbiter and Huygens lander work and how we use the powerful suite of science instruments with this engaging 3D model.

Behind the Scenes

Behind the Scenes

A glimpse at the men and women behind the exploring machines.