Here’s an amazing portrait of Tethys, a 662-mile-wide, airless and heavily-cratered moon of Saturn. The photo was taken by Cassini on October 14, 2009, with the moon fully lit by the sun. Its high reflectivity (albedo) indicate a large amount of ice in its composition. I adjusted the image to bring out the details in…
Tag: Cassini
A Rhea View
Here’s an amazingly detailed view of the extensively cratered surface of Rhea, Saturn’s second-largest moon, taken during a particularly close encounter by Cassini on October 13, 2009. About 950 miles wide Rhea is less than a third the size of Titan, Saturn’s largest moon. Unlike Titan, Rhea has no atmosphere at all to speak of…
A Cratered Crescent Composition
The crescent of Saturn’s moon Tethys hovers serenely over a dimly-lit ringplane in this raw image, taken by the Cassini orbiter on October 11, 2009. Frigid, airless and heavily-cratered, Tethys is mostly composed of water ice and rock. It is 662 miles wide. Image: NASA/JPL/SSI
Saturn in the Spring
The Cassini Imaging Team has released this image, a stunning portrait of Saturn made from 75 separate wide-angle exposures taken during the ringed planet’s spring equinox on August 12, 2009. The specific angle of sunlight during the equinox makes the shadow of Saturn’s expansive rings appear as a pencil-thin line across the cloudtops at the…
Look on the Bright Side
Another view of Saturn’s moon Iapetus (see previous post) shows the brighter surface illuminated by the sun, with a section of the darker surface visible near the moon’s equator. This dual-coloration of the 914-mile-wide moon was first observed by Giovanni Cassini in 1671. Noticing that the moon was only visible when on the western side…
Spokes and Shadows
This animation, made up of several raw images from the Cassini spacecraft, shows the mysterious features known as spokes in Saturn’s B ring. These spokes, thicker regions of material within the otherwise uniform rings, were first observed by Voyager in 1980 and have yet to be have their mechanics explained by scientists. Theories range from…
A Fresh Perspective
Prometheus’ shadow slices through the strands of Saturn’s F ring in this low-angle view from the Cassini orbiter. The sunlit shepherd moon is a bit overexposed in this image, in order to capture the bands of the rings. This view is looking outwards across the edge of the B ring (at lower left), the darker…
Shadow Play
A series of images from Cassini shows the 110-mile-wide Janus passing through shadows cast by Saturn’s rings. Janus shares its orbit within the ring system with sister moon Epimetheus. Both are small, rocky worlds…irregularly-shaped clusters of rubble pockmarked by ancient craters and displaying lots of scrapes and gouges, evidence of glancing blows by larger bodies.
Around the Track
Shepherd moons Prometheus and Daphnis race around Saturn’s rings within their respective gaps, affecting the ring material in their own distinct ways. Prometheus, on the left side, pulls the bright, ropy F ring into streamers while tiny Daphnis, embedded in the 25-mile-wide Keeler gap at lower center, sends up a mound of darker A ring…
Smooth as Glass
The dark spot in the middle of this image is Ontario Lacus, possibly a shallow lake filled with liquid methane located near the south pole of Titan, imaged with synthetic-aperture radar by Cassini. Ontario Lacus on Titan covers about 5,800 square miles in area—about four-fifths the size of Lake Ontario here on Earth.
Worlds Great and Small
A wonderful raw image from the Cassini spacecraft showing a crescent-lit Saturn and one of its 61 known moons. Honestly I’m not sure which moon this is. Could be Tethys, could be Titan, it’s hard to make out in this wide-angle view. Also in crescent, its night side is dimly lit by reflected “Saturnshine”. Cassini…
Rings in Relief
This wide-angle view from Cassini, taken on August 16 (2009), shows an amazing amount of relief across the surface of Saturn’s A ring as well as a long shadow cast by the wake of the shepherd moon Daphnis within the Keeler gap. 4.3-mile-wide Daphnis, almost too small to be seen here, sculpts the edges of…
Lights in the Dark 