The Cassini spacecraft orbiting Saturn has returned radar imagery of dunes on the moon Titan, the only moon in our solar system to have an atmosphere. Radar allows a view of what is hidden by the atmospheric haze: Titan’s Dunes and Other Features Emerge in New Images – Cassini/NASA

This synthetic-aperture radar (SAR) image was obtained by
NASA’s Cassini spacecraft on July 25, 2016, during its “T-121”
pass over Titan’s southern latitudes.

The video shows some of the radar imagery.

This video focuses on Shangri-la, a large, dark area on Titan filled with dunes. The long, linear dunes are thought to be comprised of grains derived from hydrocarbons that have settled out of Titan’s atmosphere. Cassini has shown that dunes of this sort encircle most of Titan’s equator. Scientists can use the dunes to learn about winds, the sands they’re composed of, and highs and lows in the landscape.

The radar image was obtained by the Cassini Synthetic Aperture radar (SAR) on July 25, 2016, during the mission’s 122nd targeted Titan encounter.

In this SETI Institute seminar,  author/artist Michael Carroll explores

the bizarre methane-filled seas and soaring dunes of Saturn’s largest moon, Titan. Recent advances in our understanding of this planet-sized moon provide enough information for authors to paint a realistic picture of this truly alien world.

On Thursday, October 28th, the Cassini spacecraft passed safely through the misty icy plume that is emitted from the Saturn moon Enceladus.  The goal was to obtain better measurements of the chemistry of the plume:

• Deepest-Ever Dive Through Enceladus Plume Completed – NASA
• Seven Key Facts About Cassini’s Oct. 28 ‘Plume Dive’

• A Tale of Two Hemispheres
• Enceladus ‘E-21’ Flyby: Deepest dive through the plume

Here is an animation of the flyby made with the new SpaceTraveler Solar System & Space Missions Simulator from BINARY SPACE:

I’m told that the orientation data of the spacecraft could not be obtained in time so there is a some possible deviation with respect to the actual orientation during the flyby. The program will be updated when the data becomes available.

More great images photos of the Saturn system from Cassini:

*Titan in front of Saturn – Val Klavans

This is an approximate true color view of Saturn and its moon Titan. Titan is seen here hovering near Saturn’s rings.

This composite is made of images that were taken by Cassini’s camera system, the Imaging Science Subsystem (ISS) on May 22, 2015 and received on Earth May 24, 2015. The camera was pointing toward Titan and Saturn, and the images were taken using the green, violet, and infrared filters.

Credit: NASA / JPL / SSI / Val Klavans

* Cassini Solstice Mission: Cassini Prepares for Last Up-close Look at Hyperion –

NASA’s Cassini spacecraft will make its final close approach to Saturn’s large, irregularly shaped moon Hyperion on Sunday, May 31.

The Saturn-orbiting spacecraft will pass Hyperion at a distance of about 21,000 miles (34,000 kilometers) at approximately 6:36 a.m. PDT (9:36 a.m. EDT). Mission controllers expect images from the encounter to arrive on Earth within 24 to 48 hours.

Mission scientists have hopes of seeing different terrain on Hyperion than the mission has previously explored in detail during the encounter, but this is not guaranteed. Hyperion (168 miles, 270 kilometers across) rotates chaotically, essentially tumbling unpredictably through space as it orbits Saturn. Because of this, it’s challenging to target a specific region of the moon’s surface, and most of Cassini’s previous close approaches have encountered more or less the same familiar side of the craggy moon.

Cassini scientists attribute Hyperion’s unusual, sponge-like appearance to the fact that it has an unusually low density for such a large object — about half that of water. Its low density makes Hyperion quite porous, with weak surface gravity. These characteristics mean impactors tend to compress the surface, rather than excavating it, and most material that is blown off the surface never returns.

Here’s a view of Hyperion when Cassini made a close pass in 2005.

* Cassini Solstice Mission: Rhea’s Horizon

Gazing off toward the horizon is thought-provoking no matter what body’s horizon it is. Rhea’s horizon is slightly irregular and battered by craters, so thoughts inevitably turn towards the forces that shape these icy worlds.

The surface of Rhea (949 miles or 1527 kilometers across) has been sculpted largely by impact cratering, each crater a reminder of a collision sometime in the moon’s history. On more geologically active worlds like Earth, the craters would be erased by erosion, volcanoes or tectonics. But on quieter worlds like Rhea, the craters remain until they are disrupted or covered up by the ejecta of a subsequent impact.

Lit terrain seen here is on the trailing hemisphere of Rhea. North on Rhea is up and rotated 12 degrees to the right. In this view, Cassini was at a subspacecraft latitude of 9 degrees North. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 10, 2015.

Rhea’s horizon