Changes in Titan's North Polar Cloud

This series of images obtained by NASA's Cassini spacecraft shows several views of the north polar cloud covering Saturn's moon Titan. The false-color images were obtained by Cassini's Visual and Infrared Mapping Spectrometer (VIMS). They can be seen on the left of each pair of images, with that same image re-projected onto a globe of Titan on the right. The global image shows Titan's north pole at the center. Other parts of the Titan globe are filled in using data from Cassini's imaging cameras and radar instrument.

The VIMS images cover 2006 to 2009, when Titan was transitioning from northern winter to northern spring. In 2006, the north polar cloud appeared dense and opaque. But in spectrometer images obtained around the 2009 equinox, when the Sun was directly over Saturn and Titan's equators and northern winter was turning into spring, the cloud appeared much thinner and patchier. It allowed scientists to see the underlying northern lakes and seas on the surface, including Kraken Mare (at the end of the red arrows). The northern seas and lakes, made of liquid hydrocarbons, look like dark jigsaw puzzle pieces in the false-color images.

Scientists colorized the VIMS image by assigning red, green and blue to the parts of the infrared spectrum around 5 micrometers, 2.8 micrometers and 2.03 micrometers, respectively. The images create a kind of time-lapse series from December 28, 2006 to June 6, 2009, from the 23rd, 24th, 30th, 43rd, 44th, 45th, 52nd, 53rd, 55th and 57th time Cassini flew by Titan. (Planning changes early in the orbital tour meant that even though a Titan flyby might be called "T22," it was actually the 23rd flyby of Titan.)

For a view of just the VIMS images, see PIA15230.

Photo credit: NASA/JPL-Caltech/University of Arizona/CNRS/LPGNantes

Snapshots of Titan's North Polar Cloud

This series of false-color images obtained by NASA's Cassini spacecraft shows the dissolving cloud cover over the north pole of Saturn's moon Titan. The images, obtained by Cassini's Visual and Infrared Mapping Spectrometer (VIMS), cover 2006 to 2009, when Titan was transitioning from northern winter to northern spring. In 2006, the north polar cloud appeared dense and opaque. But in spectrometer images obtained around the 2009 equinox, when the Sun was directly over Saturn and Titan's equators and northern winter was turning into spring, the cloud appeared much thinner and patchier. The dissipating cloud allowed scientists to see the underlying northern lakes and seas, including Kraken Mare. The northern seas and lakes on the surface below, made of liquid hydrocarbons, look like dark jigsaw puzzle pieces in the false-color images.

Scientists colorized the VIMS image by assigning red, green and blue to the parts of the infrared spectrum around 5 micrometers, 2.8 micrometers and 2.03 micrometers, respectively. The images create a kind of time-lapse series from December 28, 2006 to June 6, 2009.

For another view of these images, see PIA15231.

Photo credit: NASA/JPL-Caltech/University of Arizona/CNRS/LPGNantes

Mimas and the Cut-Off Rings

Saturn's moon Mimas joins the planet's rings which appear truncated by the planet's shadow in this Cassini spacecraft image.

Saturn is off to the left, out of view here. The inner rings are just visible there. But the planet's shadow covers part of the rings across the middle of the image. Mimas (246 miles, or 396 kilometers across) is closer to Cassini than the rings are here.

The bright speck above the rings is a star.

To increase visibility, the rings have been brightened by a factor of two relative to Mimas. This view looks toward the southern, unilluminated side of the rings from just below the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on December 21, 2011. The view was obtained at a distance of approximately 1.7 million miles (2.7 million kilometers) from Mimas. Image scale is 10 miles (16 kilometers) per pixel on Mimas.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Rhea Before Titan

Craters appear well defined on icy Rhea in front of the hazy orb of the much larger moon Titan in this Cassini spacecraft view of these two Saturn moons.

See PIA08137 and PIA14913 to learn more about the hazy atmosphere on Titan (3,200 miles, or 5,150 kilometers across). See PIA07763 and PIA11465 for closer views of craters on Rhea (949 miles, or 1,528 kilometers across).

Lit terrain seen here is on the leading hemispheres of Rhea and Titan. North on the moons is up and rotated 13 degrees to the left. The limb, or edge of the visible disk, of Rhea is slightly overexposed in this view.

The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on December 10, 2011. The view was acquired at a distance of approximately 1.2 million miles (2 million kilometers) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 109 degrees. The view was acquired at a distance of approximately 810,000 miles (1.3 million kilometers) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 109 degrees. Image scale is 8 miles (12 kilometers) per pixel on Titan and 5 miles (8 kilometers) per pixel on Rhea.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Enceladus and Saturn's Rings

A crescent Enceladus appears with Saturn's rings in this Cassini spacecraft view of the moon.

The famed jets of water ice emanating from the south polar region of the moon are faintly visible here. They appear as a small white blur below the dark south pole, down and to the right of the illuminated part of the moon's surface in the image. The image's contrast was enhanced to increase the visibility of the jets. See PIA11688 to learn more about the jets.

Lit terrain seen here is on the trailing hemisphere of Enceladus (313 miles, 504 kilometers across). North on Enceladus is up.

This view looks toward the northern, sunlit side of the rings from just above the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on January 4, 2012. The view was obtained at a distance of approximately 181,000 miles (291,000 kilometers) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 136 degrees. Image scale is 1 mile (2 kilometers) per pixel.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Note: For more information, see Saturn's Rings and Enceladus.

Saturn and Dione

Saturn and Dione appear askew in this Cassini spacecraft view, with the north poles rotated to the right, as if they were threaded along on the thin diagonal line of the planet's rings.

This view looks toward the anti-Saturn side of Dione (698 miles, or 1,123 kilometers across). North on Dione is up and rotated 20 degrees to the right. This view looks toward the northern, sunlit side of the rings from less than one degree above the ring plane.

The image was taken in visible green light with the Cassini spacecraft wide-angle camera on December 12, 2011. The view was obtained at a distance of approximately 35,000 miles (57,000 kilometers) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 41 degrees. Image scale is 2 miles (3 kilometers) per pixel on Dione.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Dune Fields on Titan and Earth

Two different dune fields on Titan: Belet (top left) and Fensal (bottom left), as imaged by Cassini's radar. The image also shows two similar dune fields on Earth in Rub Al Khali, Saudi Arabia.

Fensal is at higher latitude and elevation than Belet and clearly shows thinner dunes with brighter and wider areas in between, suggesting less abundant dune material in this region.

Photo credit: NASA/JPL-Caltech/ASI/ESA and USGS/ESA

Note: For more information, see Cassini's Radar Observes Titan's Tropical Dune Fields; also, PIA15225: Dune Patterns.

Mimas Behind Dione

Saturn's moon Mimas peeks out from behind the night side of the larger moon Dione in this Cassini image captured during the spacecraft's December 12, 2011, flyby of Dione.

Dione is 698 miles, or 1,123 kilometers, across and its day side dominates the view on the right of the image. Smaller Mimas is on the left and measures 246 miles, or 396 kilometers, across.

Lit terrain seen here is on the Saturn-facing side of Mimas and in the area between the trailing hemisphere and anti-Saturn side of Dione. North on the moons is up and rotated 20 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 58,000 miles (94,000 kilometers) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 42 degrees. Image scale is 1,833 feet (559 meters) per pixel on Dione. The view was obtained at a distance of approximately 380,000 miles (611,000 kilometers) from Mimas and at a Sun-Mimas-spacecraft, or phase, angle of 41 degrees. Image scale is 2 miles (3 kilometers) per pixel on Mimas.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Closest Flyby of Dione

Flying past Saturn's moon Dione, Cassini captured this view which includes two smaller moons, Epimetheus and Prometheus, near the planet's rings.

The image was taken in visible light with Cassini's narrow-angle camera during the spacecraft's flyby of Dione on December 12, 2011. This encounter was the spacecraft's closest pass of the moon's surface, but, because this flyby was intended primarily for other Cassini instruments, it did not yield Cassini's best images of the moon. Higher resolution images were obtained during earlier flybys (see PIA07638).

Dione (698 miles, or 1,123 kilometers across) is closest to Cassini here and is on the left of the image. Potato-shaped Prometheus (53 miles, or 86 kilometers across) appears above the rings near the center top of the image. Epimetheus (70 miles, or 113 kilometers across) is on the right.

This view looks toward the northern, sunlit side of the rings from less than one degree above the ring plane. The view was acquired at a distance of approximately 67,000 miles (108,000 kilometers) from Dione. Image scale is 2,122 feet (647 meters) per pixel on Dione.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Titan and Tethys Behind the Rings

The line of Saturn's rings disrupts the Cassini spacecraft's view of the moons Tethys and Titan.

Larger Titan (3,200 miles, or 5,150 kilometers across) is on the left. Tethys (660 miles, or 1,062 kilometers across) is near the center of the image. This view looks toward the Saturn-facing sides of Tethys and Titan. The angle also shows the northern, sunlit side of the rings from less than one degree above the ring plane.

The image was taken in visible red light with the Cassini spacecraft narrow-angle camera on December 7, 2011. The view was acquired at a distance of approximately 1.4 million miles (2.2 million kilometers) from Tethys and 1.9 million miles (3.1 million kilometers) from Titan. Image scale is 8 miles (13 kilometers) per pixel on Tethys and 12 miles (19 kilometers) on Titan.

Photo credit: NASA/JPL-Caltech/Space Science Institute