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Headshot of Emily Lakdawalla

Lots of great stuff in the latest Cassini data release

Posted by Emily Lakdawalla

13-04-2011 16:56 CDT

Topics: Enceladus, Dione, pretty pictures, Titan, amateur image processing, Saturn's small moons, global views, Saturn's moons, many worlds, Saturn's rings

I've got some lovely pictures from Saturn to show you! Every three months, the Cassini mission dumps gigabytes worth of precious Saturn data into the Planetary Data System, and the latest gift came on April 1. This particular pile of data, which was taken between April 1 and June 30, 2010, contains a lot of really terrific moon observations. You can browse the images through the OPUS search tool. To go directly to the latest release, you can look at volumes 2062 and 2063). If any of you are using Björn Jónsson's database to search for cool images, I've uploaded the updates that describe both volumes.

Here's some of the images that caught my eye as I browsed this latest release. There was a super close flyby of Dione, which gave us this lovely view of its scarps. I don't understand why the icy faces of the scarps look so smooth, almost wispy. In a couple of spots I swear I can see layers exposed in the scarp walls.

Dione's scarps and slopes


Dione's scarps and slopes
Cassini snapped this ultra-close view of Dione during its 500-kilometer flyby on April 7, 2010.

What's weird is that only a couple of minutes before that photo, Cassini took this one, which looks utterly different. If I didn't know this was Dione I would have assumed that it was the Moon.

Dione does its best Moon impression


Dione does its best Moon impression
Taken during the April 7, 2010 close flyby of Dione at an altitude of only about 1,500 kilometers, this Cassini image captures a bit of cratered terrain lacking obvious signs of Dione's icy nature.

Here's a nice color portrait of Janus.


NASA / JPL / SSI / color composite by Emily Lakdawalla

Cassini took the four photos used to compose this enhanced-color view of Janus on April 7, 2010 from a distance of 74,800 kilometers.

Here's an incredibly skinny crescent Dione. Cassini was looking at Dione at such high phase in order to try to see plumes, but as far as I know, nobody's seen Dione behaving anything like Enceladus.

Dione's crescent


Dione's crescent
An extremely thin crescent view of the icy moon Dione, captured by Cassini on May 17, 2010. The phase angle here is 151 degrees.

I thought this was a nice color portrait of Enceladus. I love the way you can see three major different types of terrain: cratered in the north, ropy ridges near the equator, tiger stripes in the south.

Enceladus in color

NASA / JPL / SSI / color composite by Emily Lakdawalla

Enceladus in color
Cassini saw a half-full Enceladus on April 7, 2010. The cratered terrain in the north contrasts with the "tiger striped" terrain in the south. The slanting dawn light on the terminator picks out Enceladus' ropy ridges in high relief.

Here's a really stunning shot that managed to grab both Pan and Daphnis in the same view, along with the funky waves they excite in the rings. I had to process this one carefully so as not to obliterate the tiny bit of you can see of Pan's shape.

Pan and Daphnis and their ring waves

NASA / JPL / SSI / processed by Emily Lakdawalla

Pan and Daphnis and their ring waves
Patterns at the outer edge of the A ring are excited by the gravitational influence of Pan, upper left, and Daphnis, near the bottom. In this image the rings have been brightened relative to the moons. Pan's saucer shape -- common for Saturn's ringmoons -- is obvious. Pan's longest axis always points toward Saturn.

Finally, at long last, the data has become available for me to do a proper job on the pic of Titan and Dione that got me accused of participating in a NASA plot to cover up alien bases.

Titan and Dione

NASA / JPL / SSI / color composite by Emily Lakdawalla

Titan and Dione
Dione passes in front of Titan in this Cassini color composite from April 10, 2010. Dione's icy surface is considerably more reflective than Titan's smoggy atmosphere. This version of the composite was composed from data archived with the Planetary Data System.
See other posts from April 2011


Or read more blog entries about: Enceladus, Dione, pretty pictures, Titan, amateur image processing, Saturn's small moons, global views, Saturn's moons, many worlds, Saturn's rings


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