This nearly 600-foot-wide pit is located on the southeastern side of Pavonis Mons, a large extinct volcano in Mars’ Tharsis region. This detailed image was taken by the HiRISE camera aboard the Mars Reconnaissance Orbiter. The idea for this close-up was suggested to the HiRISE team by a team of seventh graders at Evergreen Middle School in Cottonwood, California, as part of the HiRISE Quest Student Imaging Challenge.
After first spotting the dark pit in a THEMIS image from the Mars Odyssey orbiter the students submitted the request for a high-resolution image to be taken by HiRISE.
Rather than being a skylight into a deeper cave or lava tube as the students initially hoped, the pit clearly has a bottom covered in sand and boulders. Still, the high resolution image showed the students how information can be gained through the use of further investigation with more precise instruments – a bit of good science, I’d say! (Now where were cool programs like this when I was in middle school??)
Pits like this can be caused by the collapse of the roof of a subsurface cave or the removal of material due to erosion or, as commonly seen in Mars’ polar regions, the sublimation of subsurface carbon dioxide ice.
The boulders on the floor of the pit range in size from about 3 feet to 15 feet wide.
In the original image the shadowed area of the pit is too dark to see within; I brightened it in Photoshop and realigned it with the rest of the image to give a sort of high-dynamic range look at the pit in its entirety.
Read the original image release on the HiRISE site here.
Credit: NASA / JPL / University of Arizona. Edited by J. Major.