Planetary surfaces never cease to amaze. Take a look at this new radar image of Titan from Cassini.

Credit: NASA/JPL-Caltech

These long, flowing curves are sand dunes on Saturn’s largest Moon, a familiar feature on an utterly alien world.

Titan has familiar features such as lakes, mountain, rivers and dunes, but it is not like Earth as we know it today. The lakes and rivers are liquid hydrocarbons like ethane, methane, and propane, the mountains made of super-solid water ice, and these sand dunes made of tiny particles of hydrocarbons, similar in size to the silicon sand grains of Earth. The similarity in size of the grains means that it behave much like our sand, thus creating comparable structures. Compare the Titan image above to, for example, these sand dunes in Namibia.

Credit: NASA

See the similarity? Now, the image of Namibia is taken in optical light, while the Titan image at top is a radar image. That means Cassini sent forth radio pulses at the surface and received the reflections that came back. The sand grains appear dark because they do not reflect the radio waves very well. Radar is the only way to see through Titan’s thick, hazy atmosphere from Cassini’s orbit around Saturn. That atmosphere, by the way? Also contains* hydrocarbons.

There are so many interesting planetary surface features to explore, as I’ve learned from putting together the image gallery set of the Earth or Not Earth app by Joe Moore. You can bet I’ll be adding this one to the deck as well! So, consider this a heads up, or even a little cheat if you will, to look for this image the next time you’re playing the games for iOS or Android. I believe this is the first image in the set of sand dunes that are NOT from either Earth or Mars. Who knows? Maybe I’ll even add the Namibia picture just to mix you up.

Enjoy! And read more about these sand dunes at the European Space Agency’s website.

*Corrected 4/14