21 October 2008

Fresh Craters

Posted by Ryan Anderson

Today marks my twenty-fourth revolution around the sun! To commemorate this momentous occasion, I am going to be a lazy blogger and just let you drool over some HiRISE images instead. The image above is a small crater in the polar layered deposits. It’s filled with ice because the crater walls keep the floor shaded, so frost can collect there. You can read more about this crater at the HiRISE site.

The second image is of dunes and what appears to be a very fresh crater near Uzer crater. The small crater in this image is surrounded by dark ejecta which hasn’t been eroded away yet. If you have a sharp eye, you can also see that there are strange raised cracks in the plains west of the small crater. My guess is that those are ridges formed when water flowed through cracked bedrock and altered the rock near the cracks, making it erosion-resistant. You can read more about this image at the HiRISE site, though they focus on the bigger crater that is outside the field of view of this close-up.