Strange fernlike ridges on Mars


Readers!
 
Scroll down to read this post.
 
For many reasons, mostly political but partly ethical, I do not use Google, Facebook, Twitter. They practice corrupt business policies, while targeting conservative websites for censoring, facts repeatedly confirmed by news stories and by my sense that Facebook has taken action to prevent my readers from recommending Behind the Black to their friends.
 
Thus, I must have your direct support to keep this webpage alive. Not only does the money pay the bills, it gives me the freedom to speak honestly about science and culture, instead of being forced to write it as others demand.

 

Please consider donating by giving either a one-time contribution or a regular subscription, as outlined in the tip jar below.


 

Regular readers can support Behind The Black with a contribution via paypal:

Or with a subscription with regular donations from your Paypal or credit card account:


If Paypal doesn'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
P.O.Box 1262
Cortaro, AZ 85652

 

You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.

Fernlike ridges on Mars

Cool image time! The two images on the right, cropped, rotated, and reduced in resolution to post here, were both taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO). To see the full resolution version of each, go to the 2009 and 2018 releases.

The 2009 release was a captioned release, whereby scientist Alfred McEwen of the science team provided his explanation of these strange features.

The dark branched features in the floor of Antoniadi Crater look like giant ferns, or fern casts. However, these ferns would be several miles in size and are composed of rough rocky materials.

A more likely hypothesis is that this represents a channel network that now stands in inverted relief. The channels may have been lined or filled by indurated materials, making the channel fill more resistant to erosion by the wind than surrounding materials. After probably billions of years of wind erosion the resistant channels are now relatively high-standing. The material between the branched ridges has a fracture pattern and color similar to deposits elsewhere on Mars that are known to be rich in hydrated minerals such as clays.

These strange fernlike features do not appear to be very common on Mars. In fact, I suspect that while Mars does have many inverted channels like this, the fernlike nature of these particular channels is unique on Mars. They are located on the floor of Antoniadi Crater, a large 240-mile-wide very ancient and eroded crater located in the Martian southern highlands but near the edge down to the northern lowlands.

In seeing the new 2018 image, I was immediately compelled to place it side by side with 2009 image to see if anything had changed in the ensuring near-decade. There are color differences, but I suspect these are mostly caused by different lighting conditions or post-processing differences. Still, the dark center to the crater in the upper left of both images suggests a change in the dust dunes there, with the possibility that some of the dust has been blown from the crater over time. Also, you can see two horizontal tracks cutting across the center of the 2018 image, which I would guess are dust devil tracks, with one more pronounced.

I can imagine some planetary geologists have spent the last few months, since the second image was taken, pouring over both photographs, and have might even located other interesting changes. And if they find no significant changes, that in itself is revealing, as it gives us a sense of the pace at which the Martian surfaces evolves.

Share

3 comments

Leave a Reply

Your email address will not be published. Required fields are marked *