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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.
 

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4. Donate by check, payable to Robert Zimmerman and mailed to
 
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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.


Rolling boulders on Mars

Boulder tracks on Mars
Click for full image.

Cool image time! The photo to the left, cropped to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on January 21, 2020, and shows several boulders at the bottom of a slope, along with the tracks those boulders made as they rolled downhill sometime in the far past.

Uphill is to the south. We know the dark spots at the end of these tracks are large boulders partly because of the wind streaks emanating away from them to the north. As the wind goes around each rock it produces eddies that produce the tracks. Based on the scale and the image resolution (about 10 inches per pixel), these boulders range in size from about one to five feet in diameter.

This image has two points of interest. First, the tracks left by the boulders seem to have a repeating pattern. My guess is that the pattern most likely formed because the boulders are not spherical in shape, and as they rolled each roll repeated a certain pattern reflecting that shape. This theory is reinforced by a close look at each boulder. Though the resolution is insufficient to resolve the boulders themselves, the pixel distribution for each strongly suggests an asymmetric shape.

Second, this image, when compared with an earlier MRO image of the same spot, taken fourteen years ago in December 2006, shows no obvious change. These tracks, and their boulders, have therefore probably sat here, as we see them, for a long time. Since there appear to be two sets of tracks, with one overlying the other, this suggests that two separate events (an earthquake or nearby impact) each time caused a bunch of boulders to break free and roll downward together, with the second set of boulder tracks crossing over the earlier set.

Establishing when those two events occurred, however, will require some on-site data, something that will likely not occur until humans roam the surface of Mars in large numbers.

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

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.

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