Launched in 1997, NASA's Cassini spacecraft spent seven years traveling to Saturn before spending the past nine-and-a-half years orbiting the massive planet, making scientific observations and returning thousands of gorgeous otherworldly images. Saturn has more than 150 known moons and the most spectacular ring system of any of our neighboring planets. Its varied satellites include massive Titan, with a thick atmosphere and lakes of liquid ethane; icy Enceladus, spewing jets of water ice far into space; and two-toned Iapetus, with a mysterious equatorial ridge of mountains. Today, on the last day of the year, I thought it would be nice to look back on some of my favorite images from Cassini over the years, as we approach a decade of orbits next summer.
The spinning vortex of Saturn's north polar storm resembles a deep red rose of giant proportions surrounded by green foliage in this false-color image from NASA's Cassini spacecraft. Measurements have sized the eye at a staggering 1,250 miles (2,000 kilometers) across with cloud speeds as fast as 330 miles per hour (150 meters per second). The view was acquired at a distance of approximately 261,000 miles (419,000 kilometers) from Saturn. (NASA/JPL-Caltech/SSI)
Saturn at equinox - the rings aligned to the sun edge-on. Illumination of the rings by sunlight reflected off the planet vastly dominates any meager sunlight falling on the rings. (NASA/JPL/Space Science Institute)
Ring shadows line the face of distant Saturn, providing an exquisite backdrop for the brilliant, white sphere of Enceladus.(NASA/JPL/Space Science Institute)
The gravity of potato-shaped Prometheus (86 kilometers, or 53 miles across) periodically creates streamer-channels in the F ring, and the moon's handiwork can be seen in the dark channels here. (NASA/JPL/Space Science Institute)
Saturn's largest and second largest moons, Titan and Rhea, appear to be stacked on top of each other in this true-color scene.(NASA/JPL/Space Science Institute)
A close view of Saturn's small moon Helene during a flyby on March 3, 2010. Helene is 33 kilometers, or 21 miles across.(NASA/JPL/Space Science Institute)
A close flyby of Dione, on October 12, 2005, approximately 14,310 miles (23,029 kilometers) away.(NASA/JPL/Space Science Institute)
Vertical structures, among the tallest seen in Saturn's main rings, rise abruptly from the edge of Saturn's B ring to cast long shadows on the ring in this image taken by NASA's Cassini spacecraft two weeks before the planet's August 2009 equinox. In this image, Cassini's narrow angle camera captured a 1,200-kilometer-long (750-mile-long) section arcing along the outer edge of the B ring. Here, vertical structures tower as high as 2.5 kilometers (1.6 miles) above the plane of the rings -- a significant deviation from the vertical thickness of the main A, B and C rings, which is generally only about 10 meters (about 30 feet). Cassini scientists believe that this is one prominent region at the outer edge of the B ring where large bodies, or moonlets, up to a kilometer or more in size, are found. It is possible that these bodies significantly affect the ring material streaming past them and force the particles upward, in a "splashing" manner.(NASA/JPL/Space Science Institute)
Cassini's closest-ever flyby of Saturn's moon Mimas, featuring the Herschel Crater, 130 kilometers, or 80 miles, wide on the right side.(NASA/JPL/Space Science Institute)
This spectacular and disorienting maze of lines is a Cassini portrait of the gas giant Saturn, its rings and its small, icy moon Mimas. The rings cast dark shadows across Saturn's northern hemisphere, creating a photonegative effect: dark sections are dense and block the Sun, while bright sections are less dense areas or gaps in the rings, which are more transparent to sunlight.(NASA/JPL/Space Science Institute)
Dark and light surfaces on the northern hemisphere of Iapetus (1,468 kilometers, or 912 miles across).(NASA/JPL/Space Science Institute)
The Cassini spacecraft looks past the cratered south polar area of Saturn's moon Rhea to spy the moon Dione and the planet's rings in the distance. (NASA/JPL/Space Science Institute)
This view looks toward the leading hemisphere of Calypso (21 kilometers, or 13 miles across), one of two Trojan moons of the larger moon Tethys. (NASA/JPL/Space Science Institute)
Less than 20 minutes after Cassini's close approach to Titan on March 31, 2005, its cameras captured this view of Saturn through Titan's upper atmosphere. The northern part of Saturn's disk can be seen at the upper left; dark horizontal lines are shadows cast upon Saturn by its rings. Below this level, Titan's atmosphere is thick enough to obscure Saturn. The image was captured at a distance of 7,980 kilometers (4,960 miles) from Titan, when Saturn was about 1.3 million kilometers (808,000 miles) away. (NASA/JPL/Space Science Institute)
This image shows the first flash of sunlight reflected off a lake on Saturn's moon Titan. The glint off a mirror-like surface is known as a specular reflection. This kind of glint was detected by the visual and infrared mapping spectrometer (VIMS) on NASA's Cassini spacecraft on July 8, 2009. It confirmed the presence of liquid in the moon's northern hemisphere, where lakes are more numerous and larger than those in the southern hemisphere. The lakes are believed to be filled with liquid ethane and methane.(NASA/JPL/University of Arizona/DLR)
Dazzling Titan glows with a 360-degree sunset as light scatters through its very extended atmosphere.(NASA/JPL/Space Science Institute)
Saturn's mysterious north polar hexagon, a massive persistent cloud structure atop the north pole.(NASA/JPL/Space Science Institute)
On October 5, 2008, Cassini captured this stunning mosaic of Enceladus, as the spacecraft sped away from a close flyby of this geologically active moon of Saturn. (NASA/JPL/Space Science Institute)
NASA's Cassini spacecraft successfully completed its October 1, 2011 flyby of Saturn's moon Enceladus and its jets of water vapor and ice. At its closest approach, the spacecraft flew approximately 62 miles (100 kilometers) above the moon's surface. The close approach was designed to give some of Cassini's instruments, including the ion and neutral mass spectrometer, the chance to "taste" the jets themselves. (NASA/JPL/Space Science Institute)
A narrow-angle image captured during the October 31, 2008, flyby of Saturn's moon Enceladus, at a distance of approximately 1,691 kilometers (1,056 miles). (NASA/JPL/Space Science Institute)
Atlas and Pan emerge from the far side of Saturn. Light passing through the upper reaches of the planet's atmosphere is refracted, or bent, distorting the image of the rings beyond. (NASA/JPL/Space Science Institute)
The Cassini spacecraft's close flyby of Epimetheus, (116 kilometers, or 72 miles across) in December 2007 returned detailed images of the moon's south polar region. (NASA/JPL/Space Science Institute)
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. (NASA/JPL/Space Science Institute)
The vortex at Saturn's north pole, seen here in the infrared. The eye of the immense cyclone is about 2,000 kilometers (1,250 miles) wide.(NASA/JPL/Space Science Institute)
As it departed its encounter with Saturn's moon Dione on October 11, 2005, Cassini sailed above an unreal landscape blasted by impacts. The rising Sun throws craters into sharp contrast and reveals steep crater walls. (NASA/JPL/Space Science Institute)
The moon Prometheus creates an intricate pattern of perturbation in Saturn's F ring while the moon Daphnis disturbs the A ring in this image taken after the planet's August 2009 equinox. (NASA/JPL/Space Science Institute)
The opposition effect, a brightness surge that is visible on Saturn's rings when the sun is directly behind the spacecraft, is captured here as a colorful halo of light moving across Saturn's sunlit rings. (NASA/JPL/Space Science Institute)
Battered Mimas (397 kilometers, or 247 miles across), seen from a distance of approximately 191,000 kilometers (119,000 miles), against the hazy limb of Saturn. (NASA/JPL/Space Science Institute)
A unique vista of Saturn's horizon, featuring clud tops and shadows. (NASA/JPL/Space Science Institute)
A quartet of Saturn's moons, from tiny to huge, surround and are embedded within the planet's rings in this Cassini composition. Saturn's largest moon, Titan, is in the background of the image. Next, the wispy terrain on the trailing hemisphere of Dione can be seen on that moon which appears just above the rings at the center of the image. Saturn's small moon Pandora orbits beyond the rings on the right of the image. Finally, Pan can be seen in the Encke Gap of the A ring on the left of the image. (NASA/JPL/Space Science Institute)
Saturn, lit from behind, while Cassini was in its shadow, on December 12, 2012. Images taken using infrared, red and violet spectral filters were combined to create this enhanced-color view. (NASA/JPL/Space Science Institute)
Detail of a disturbance in Saturn's F ring, including evidence for the perturbing effect of small moonlets orbiting in or close to the ring's bright core. For some time, scientists have suspected the presence of tiny moonlets that orbit Saturn in association with the clumpy ring. As the small satellites move close to the F ring core they leave a gravitational signature. In some cases they can draw out material in the form of a "streamer". (NASA/JPL/Space Science Institute)
Saturn's fourth-largest moon, Dione, can be seen through the haze of the planet's largest moon, Titan, in this view of the two posing before the planet and its rings from NASA's Cassini spacecraft, in December of 2011. (NASA/JPL/Space Science Institute)
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