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My July fund-raising campaign, celebrating the 13th anniversary of the start of this website, has now ended. This was the second most successful monthly fund-raising campaign ever. Thank you again to everyone who has who donated or subscribed. It is difficult to explain what your support means to me.


You can still donate or subscribe to support my work if you wish, 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:

4. A Paypal subscription:

5. Donate by check, payable to Robert Zimmerman and mailed to
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c/o Robert Zimmerman
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Finding Martian glaciers from orbit

Glacier flow on Mars
Click for full image.

Today’s cool image is a great example of the surprises one can find by exploring the archive of the high resolution pictures that Mars Reconnaissance Orbiter (MRO) has produced since it arrived in Mars orbit back in 2006. The picture to the right, rotated, cropped, and reduced to post here, was taken by MRO’s high resolution camera back on May 4, 2017. I only found it because I had picked out a October 24, 2022 high resolution image that covered a different area of this same flow feature just to the north east. In trying to understand that 2022 picture I dug to see other images had been taken around it, and found the earlier 2017 photo that was even more interesting.

Neither however really covered the entire feature, making it difficult to understand its full nature. I therefore searched the archive of MRO’s context camera, which has imaged the entire planet with less resolution but covering a much wider area per picture. The context camera picture below captures the full nature of this feature.

Context camera view of glacier
Click for full image.

Overview map

The photo to the right was taken on December 24, 2012, ten years ago. It shows a spectacular glacier-like flow that has pushed its way through a gap in a mountain ridge. The white box shows the area covered by the high resolution photo above.

Since 2012 scientists have photographed this flow feature multiple times to see if over time they can detect any motion or change. Changes, including sublimation, would suggest the glacier is shrinking. Motion would suggest the glacier is growing. No change suggests a steady-state condition and an inactive glacier. All three would tell us a great deal about the larger Martian climate. At the resolution available online, however, it is impossible to detect any changes, though a much closer look might tell us differently.

The white dot on the overview map to the right indicates location of this flow feature, at the head of Harmakhis Valles, one of several meandering canyons that cut their way downhill into Hellas Basin, the death valley of Mars. All of these valleys sit in the 30 to 55 degree latitude band where many Martian glaciers are found, and all three appear from many images to be each filled for most of their length with a massive glacier. (If you search Behind the Black for “Dao”, “Harmakhis”, or “Reull” you can see many examples.)

With today’s cool image, we appear to be looking at the beginnings of the Harmakhis Valles glacier.

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 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

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