Click for full image.
Cool image time! The photo to the right, cropped to post here, was yesterday’s captioned image from the MRO science team. From the caption, written by Shane Byrne of the Lunar and Planetary Lab University of Arizona,
About a third of Mars has water ice just below the dusty surface. Figuring out exactly where is vital for future human explorers. One of the ways scientists do this is to look for landforms that only occur when this buried ice is present. These scallops are one of those diagnostic landforms.
A layer of clean ice lies just below the surface in this image. As the ice ablates away in some spots the surface dust collapses into the hole that’s left. These holes grow into the scallops visible here as more and more ice is lost.
You can see those holes near the top of the scallop’s slopes.
This particular set of scallops is located just south of Hellas Basin at latitude 58 degrees south, in a region where many such scallops have been found. It is also the same region where scientists have located evidence of ice in the cliffs of scarps, similar to the scallops but much steeper. While the formation processes for the scallops and scarps are probably similar, they might not be exactly the same, as Byrne explained to me in an email.
They’re similar in that they form in the same surface water ice layer from sublimation. We don’t really understand how the icy scarps form though. The scallops are easier to explain.
A September 2020 cool image post of similar scallops in this same region covered these same questions, noting especially that it only takes a layer of dust and debris a mere four inches thick to protect the ice from sublimating away. Therefore, there could be a lot of undiscovered ice on Mars, as yet unseen because no landforms, such as scallops, suggest its presence just under the surface.
I must unfortunately ask you for your financial support because I do not depend on ads and rely entirely on the generosity of readers to keep Behind the Black running. You can either make a one time donation for whatever amount you wish, or you sign up for a monthly subscription ranging from $2 to $15 through Paypal or $3 to $50 through Patreon.
Your support will allow me to continue covering science and culture as I have for the past twenty years, independent and free from any outside influence.
Your support is even more essential to me because I not only keep this site free from advertisements, I do not use the corrupt social media companies like Google, Twitter, and Facebook to promote my work. I depend wholly on the direct support of my readers.
You can provide that support to Behind The Black with a contribution via Patreon or PayPal. To use Patreon, go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation. For PayPal click one of the following buttons:
If Patreon or Paypal don't work for you, you can support Behind The Black directly by sending your donation by check, payable to Robert Zimmerman, to
Behind The Black
c/o Robert Zimmerman
Cortaro, AZ 85652
Or you can donate by using Zelle through your bank. You will need to give my name and email address (found at the bottom of the "About" page). The best part of this electronic option is that no fees will be deducted! What you donate will be what I receive.