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Dawn Finds Similarities Between Ceres and Saturn’s Moons

Ceres (left, Dawn image) compared to Tethys (right, Cassini image) at comparative scale sizes. (Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA and NASA/JPL-Caltech/SSI. Comparison by J. Major.)

Ceres (left, Dawn image) compared to Tethys (right, Cassini image) at comparative scale sizes. (Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA and NASA/JPL-Caltech/SSI. Comparison by J. Major.)

Around 600 miles wide, covered in craters and cliffs, a composition of rock and water ice… these are descriptions of both several of Saturn’s moons and the dwarf planet Ceres, based on recent observations by NASA’s Dawn spacecraft. New topographical maps show that, in terms of surface features anyway, Ceres shares similarities with Saturn’s icy satellites.

“The craters we find on Ceres, in terms of their depth and diameter, are very similar to what we see on Dione and Tethys, two icy satellites of Saturn that are about the same size and density as Ceres,” said Paul Schenk,  Dawn science team member and a geologist at the Lunar and Planetary Institute (LPI) in Houston, TX. “The features are pretty consistent with an ice-rich crust.”

Read more in my article on Universe Today.

Mighty Melanthius

Raw image from Cassini acquired on April 14, 2012.

The 662-mile-wide Tethys is one of the most heavily cratered worlds in the solar system, tied with sister moons Rhea and Dione. In this recent raw image captured by Cassini on April 14, we can see some of the moon’s larger craters, including Melanthius with its enormous central peak. Read the rest of this entry

A Little Pas de Deux: Tethys and Dione

Saturn's moons Tethys and Dione pass each other from Cassini's point of view. (CLICK TO PLAY)

Saturn’s moon Tethys, its giant Odysseus crater in plain view, passes in front of of the slightly darker Dione in this animation made from several raw images acquired by Cassini earlier this month. Pretty cool!

Read the rest of this entry

Ride Along With Rhea

Animation made from raw Cassini image data acquired April 25, 2011

Assembled from 29 raw images taken by the Cassini orbiter on Monday, April 25, this animation brings us along an orbital ride with Rhea as it crosses Saturn’s nighttime face, the planet’s shadow cast across the ringplane. Sister moons Dione and Tethys travel the opposite lane in the background, eventually appearing to sink into Saturn’s atmosphere.

Read the rest of this entry

Tethys and Saturn



660-mile-wide Tethys orbits in front of Saturn and the rings in this image from Cassini, taken on March 8, 2011. The rings cast their shadows onto the Saturn’s southern equatorial cloudtops as the planet continues moving into its summer season.

The 155-mile-wide Melanthius Crater can be seen near Tethys’ south pole.

A smaller moon can also be seen near the rings, perhaps Enceladus? Not quite sure on that one, it’s a bit too small to make out. :)

This was originally a monochrome raw image…I colored it using the RGB composite results from this image upload to give Saturn its slight hue.

Image: NASA / JPL / SSI. Edited by J. Major.


Dione and Tethys in Passing

Two of Saturn’s moons pass each other from Cassini’s perspective on December 6, 2010, in this animation compiled from 70 raw image files.

This was more an experiment in using iMovie HD to create an animation from a lot of individual images than anything else…I didn’t take the time to clean up the specks and streaks on each image, or align each frame to the next. It jumps about a bit more then I’d like, but at least I have another way of making animations now.

If you watch closely in 720p, you can make out the moons rotating, especially Tethys in the background. Keep an eye on Odysseus Crater as it edges closer to the terminator line…pretty cool! :)

Images: NASA / JPL / Space Science Institute. Animation by J. Major.

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