Surrealist Scene on the Red Planet
I was going to write about the Brian the Bat today, and his apparently untimely demise during the launch of Space Shuttle Discovery a few days ago, but I see that Ian O’Neill over at Universe Today has covered it nicely, so go check it out. Instead, I’m going to give you another gorgeous scene from our favorite planet (at least here at the Rambling Hacienda)–Mars. This one is absolutely stunning in its detail — a set of dunes in Proctor Crater in the southern hemisphere of the planet. Click on it to get the big view and just feast your eyes. Then come back here for a discussion of it.
This view was snapped by the High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter, and it shows what geologists call aeolian bedforms. The term aeolian is used to indicate “wind-blown” materials that were blown across the surface and deposited in features like these dunes and ripples.
On this image, the relatively small ridges are ripples made up of very fine sand mixed with a bit of larger sand bits and granules of rock. The larger dunes are made of sand as well and they move faster across the surface than the ripples do. All of the material you see here is made of rocks that once flowed from volcanoes (known as basaltic lavas).
What I really find very cool is to study the large version of this image (which you can get to by clicking on this smaller one — it may take a bit to open — it’s big). Do that and you can see even finer ripples in the dark areas and ripples within ripples within ripples in the brighter areas. It’s just amazing detail and I want to be there digging into the sand with my geologist’s shovel and taking samples!!
