To read this post please scroll down.

 

Readers!

 

It is now July, time once again to celebrate the start of this webpage in 2010 with my annual July fund-raising campaign.

 

This year I celebrate the fifteenth anniversary since I began Behind the Black. During that time I have done more than 33,000 posts, mostly covering the global space industry and the related planetary and astronomical science that comes from it. Along the way I have also felt compelled as a free American citizen to regularly post my thoughts on the politics and culture of the time, partly because I think it is important for free Americans to do so, and partly because those politics and that culture have a direct impact on the future of our civilization and its on-going efforts to explore and eventually colonize the solar system.

 

You can’t understand one without understanding the other.

 

Please consider supporting my work here at Behind the Black. Your help allows me to do this kind of intelligent independent analysis you don’t find elsewhere. I take no advertising or sponsors, so my reporting isn’t influenced by donations by established companies or political movements. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.

 

You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:

 

1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.

 

2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
 

3. A Paypal Donation or subscription:

 

4. Donate by check, payable to Robert Zimmerman and mailed 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 or shown in the menu above.


Very peculiar flow features on Mars

Peculiar flows on Mars
Click for full image.

Today’s cool image focuses on one of the weirdest flow features I have yet seen on Mars. The first photo to the right, rotated and cropped to post here, comes from a January 27, 2021 picture by the high resolution camera on Mars Reconnaissance Orbiter (MRO). This cropped section focuses on the middle of three such weird features, two close flows heading downhill on the interior rim of very eroded 28-mile-wide crater. For some reason the flows also have depressions on their crowns. The depressions almost look like someone carved them out with a spackling spatula. In fact, the MRO science team agrees, labeling this image as “Spatulate Depressions with and without Upslope Gullies.”

The second image to the right shows a wider crop of the same picture, and explains the reason for the last half of that label.

Wider view of peculiar flows

In this view you can see that the left two flows both have gullies uphill from them, while the right two do not. That of the middle two flows, so close together, only the left has an uphill gully is even more striking.

This crater is at 38 degrees south latitude in the southern cratered highlands, so it is possible that these lobate flows are signaling the existence of water ice below ground. Moreover, the uphill gullies for the two left flows suggests they are the source from which the material of those flows originated. That the right flows don’t have gullies however suggests otherwise, that the gullies and the lobate flows are not directly related.

But why do these flows have those interior depressions? I can make two wild guesses. First, maybe when these flows occurred they happened quickly, so that the flow front outpaced the material following, leaving more material at the head than behind it. Second, maybe the ice in the crowns of these flows had become exposed and began sublimating away, leaving the present depressions. The higher edge did not sublimate because it is made of the dust and debris, not ice, that the flow pushed ahead of it.

Wide view of crater
Click for full image.

The last image to the right, rotated, cropped, and reduced to post here, was taken by the wide view context camera on MRO. It shows the entire western half of this crater, with the white box marking the location of the second image above.

The impression left of the crater’s interior is that it has ice below the surface, and that this is sublimating away to leave the cracks and canyons, while also removing supporting material at the base of the rim and thus causing the type of avalanches geologists call mass wasting. The flows above are typical of that kind of avalanche.

The interior depressions in the flows however remain a puzzle. While I personally favor my second hypothesis, that the ice inside these flows has sublimated away, leaving a depression surrounded by the flow’s moraine, I have no enthusiasm for that explanation.

Above all, the most significant aspect of these features, despite their strangeness, is that they once again reveal the likelihood of underground ice in the mid-latitudes of Mars. There’s ice in them hills!

Genesis cover

On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

 

The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.


The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
 

"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News

3 comments

Readers: the rules for commenting!

 

No registration is required. I welcome all opinions, even those that strongly criticize my commentary.

 

However, name-calling and obscenities will not be tolerated. First time offenders who are new to the site will be warned. Second time offenders or first time offenders who have been here awhile will be suspended for a week. After that, I will ban you. Period.

 

Note also that first time commenters as well as any comment with more than one link will be placed in moderation for my approval. Be patient, I will get to it.

Leave a Reply

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