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Headshot of Emily Lakdawalla

Pretty picture: newly processed high-res view of a fractured icy moon, Dione

Posted By Emily Lakdawalla

04-12-2013 11:38 CST

Topics: Dione, pretty pictures, Cassini, amateur image processing, best of, global views, Saturn's moons

Here's a lovely new view of Dione, one of the lovely mid-sized icy moons of Saturn, assembled by Daniel Macháček. Please make sure to click through twice to appreciate its fully detailed glory. The data are about two years old. It takes a lot of work to assemble such a lovely, seamless mosaic, especially in color. Kudos to Daniel!

Super high-resolution global view of Dione, plus rings

NASA / JPL / SSI / Daniel Macháček

Super high-resolution global view of Dione, plus rings
This super high-resolution view of Dione is a mosaic of 14 footprints, images taken through infrared, green, and ultraviolet filters processed to approximate the color that the human eye would see. In the background, Saturn's ring system is foreshortened to a thin double yellow line.

Longtime readers have seen other products from this set of observations before. I put together a smaller mosaic that included some of Dione plus more of Saturn's ringmoons, but it wasn't in color:

Dione in front of ringmoons

NASA / JPL / SSI / mosaic by Emily Lakdawalla

Dione in front of ringmoons
Cassini captured the images for this mosaic on December 12, 2011. The five images used in this mosaic were taken sequentially, and the background moons shifted positions between frames; this composition does not actually reflect a confluence of moons that happened at one distinct moment in time. From left to right, the ringmoons are Prometheus, Epimetheus, and Pandora.

And here's a view from the wide-angle camera, which gathers in Saturn as well, albeit at a lower resolution:

Dione and Saturn and an almost invisible ring

NASA / JPL / SSI / Emily Lakdawalla

Dione and Saturn and an almost invisible ring
An infrared-green-violet approximate true-color composite of Dione poised in front of Saturn on December 12, 2011. Cassini is almost precisely in the ring plane, so the rings are vanishingly thin.

There are so many more equally lovely observations just waiting in the Cassini archives for someone to come along and do the work to assemble them! The data set will keep amateurs (not to mention professionals!) busy for years to come.

See other posts from December 2013


Read more blog entries about: Dione, pretty pictures, Cassini, amateur image processing, best of, global views, Saturn's moons


Donald Morrow: 12/04/2013 12:04 CST

What causes the scratches on the surface?

Saul Cohen: 12/04/2013 12:34 CST

According to Dione’s spectral and geological properties, "Cassini images have revealed that the lineaments represent sets of parallel deep, wide graben, scarps, or troughs, in parts with interstitial horsts, indicative of extensional and shear stresses. Ridges that may imply compressional stresses also occur on Dione but not in the local region observed by VIMS at high spatial resolution." So that is, it cracked when the water ice expanded during freezing or while the crust shifted around. There are some other theories about them being cryovolcanic vents, but I think these are disfavored by Cassini data.

Saul Cohen: 12/04/2013 12:35 CST

Hmm, my link didn't work. The paper cited is

Donald Morrow: 12/05/2013 06:17 CST

@Saul, Thanks!

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