My annual February birthday month fund-raising campaign for Behind the Black is now over. It was the best February campaign ever, and the second best of all of my month-long fund-raising campaigns.


There were too many people who contributed to thank you all personally. If I did so I would not have time for the next day or so to actually do any further posts, and I suspect my supporters would prefer me posting on space and culture over getting individual thank you notes.


Let this public thank suffice. I say this often, but I must tell you all that you cannot imagine how much your support means to me. I’ve spent my life fighting a culture hostile to my perspective, a hostility that has often served to squelch my success. Your donations have now allowed me to bypass that hostility to reach a large audience.


Even though the February campaign is over, if you still wish to donate or subscribe you still can do so. 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
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Mars rover update: June 23, 2017

Summary: Curiosity continues up hill. Opportunity has wheel problems.


For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

The march up Mt Sharp continues. Since my last update on May 15, Curiosity has continued working its way up towards what the science team has named Vera Rubin Ridge, the beginning of a lighter, yellowish layer of rock, dubbed the Hematite Unit, that sits higher up the mountain’s slope. They have been traveling on the Murray Formation now for more than a year, since March, 2016, so entering this new layer of geology is eagerly anticipated by the science team. (This October 3, 2016 press release. gives an overall picture of the geology Curiosity is traversing.)

Reader Phil Veerkamp sent me a beautiful panorama he stitched together from recent Curiosity images of Vera Rubin Ridge, directly to the south of the rover and higher up hill. Below is a reduced resolution version. Be sure you click on it to explore the full resolution image. This is a new type of terrain, significantly different than anything Curiosity has seen up to now. It also appears that the rover will see far less dust, and might be traveling mostly over solid boulders. Below I have cropped out a very small section of the ridge line near the center of the full image, just to illustrate this.

Low resolution image of Vera Rubin Ridge

The top of Vera Rubin Ridge

Below is a cropped annotated section of the most recent traverse map showing Curiosity’s location as well as the view shown in the above panorama. I have also indicated with the dotted yellow line where they are heading to get up on the ridge. They need to circle around the sand dune and then work their way up the slopes to the east. Travel should get significantly more interesting in the coming weeks.

Curiosity's location, sol 1732


For the overall context of Opportunity’s travels at Endeavour Crater, see Opportunity’s future travels on Mars.

Opportunity traverse map through sol 4734, mid-May 2017

Since my my May 15th update, the Opportunity science team has been acting like an expectant father. They had reached the head of Perseverance Valley in mid-May, but since then they have been gingerly pacing back and forth, studying the valley from the top and the side without entering it. The traverse map above shows their travels for the first two weeks after their arrival, but it is also a month old. While they haven’t yet posted an updated traverse map, my daily review of the images sent back each day suggests that, through June 4, they continued their pacing at the head of the valley, sometimes easing downward a bit, but never entering the valley itself.

They initially had two reasons for not entering the valley immediately. First there is fear, fear that once they go in they will not be able to get out. The gully has a steep slope and they are unsure of the stability of its surface material. As they have paced they have been studying its make-up from a distance in order to plan a safe route down. Second there is science. Once they enter the gully, they will have disturbed its flow patterns. Before they do that they want to document as much as possible those patterns, which can tell them much about what caused the flow. While liquid water is considered the most likely candidate, there is no guarantee that is the case. Wind is also a possible cause.

Today, they issued this color image of the gully, one of many taken during the past seven weeks. Below is a reduced resolution version. If you look close you can see the faint drainage swales going downhill from the left to the right in the center of the image.

Gully flowing down into Endeavour Crater

Since June 4th, however, they have had a third and more serious reason for not entering the valley, and in fact have not moved the rover much at all, because of a new problem with the left-front wheel.

The rover experienced a left-front wheel steering actuator stall on Sol 4750 (June 4, 2017), leaving the wheel toed out by 33 degrees. Our initial attempts to straighten the wheel failed to yield any results and were suggestive of a mechanical cause for the stalls (in the steering actuator). Fortunately, however a repeat of the diagnostics on Sol 4763 (June 17, 2017), added a twist that may have made a difference. In addition to attempting to actuate the steering at different voltages in a straightening (toe-in) direction, the team also commanded very small (half degree) actuations in the toe-out direction in between the straightening attempts. While these also stalled, the very last straightening attempt appeared to break free from whatever was impeding it and steered the wheel to straight.

This very good result was tempered by the fact that we still do not know for certain what the cause of the stalls was and whether the problem could reoccur.

Therefore, Opportunity will be exercising a precautionary partial moratorium on usage of the steering actuators for the foreseeable future. Specifically, this directs no front usage of steering actuators and only rear usage as circumstances might demand. Instead, tank turning and steering will be used wherever possible. The first nominal drive under these new restrictions was executed on Sol 4766 (June 20, 2017).

It remains to be seen whether they will risk the rover and go down into the gully. I suspect they will do some further pacing on the rim, testing their legs you might say, before making any decision.

Pioneer cover

From the press release: From the moment he is handed a possibility of making the first alien contact, Saunders Maxwell decides he will do it, even if doing so takes him through hell and back.

Unfortunately, that is exactly where that journey takes him.

The vision that Zimmerman paints of vibrant human colonies on the Moon, Mars, the asteroids, and beyond, indomitably fighting the harsh lifeless environment of space to build new societies, captures perfectly the emerging space race we see today.

He also captures in Pioneer the heart of the human spirit, willing to push forward no matter the odds, no matter the cost. It is that spirit that will make the exploration of the heavens possible, forever, into the never-ending future.

Available everywhere for $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from the ebook publisher, ebookit.


  • Edward

    Phil Veerkamp,
    Thank you for creating that wonderful panorama. It is truly beautiful.

    Thank you for pointing out the full resolution image. I would have missed it otherwise.

    I love that you are getting crowdsource content. It shows the enthusiasm that your readers have for your site and your reporting.

  • wayne

    good stuff.
    I echo your comments.

  • wodun

    Excellent update as always.

    What program do you use to annotate the pictures?

  • wodun asked, “What program do you use to annotate the pictures?”

    I use Gimp. As you probably know, based on past posts here, I work on a Linux computer. I also try to use as many open source programs as possible. Gimp is a truly excellent graphics program. I have been using it for more than two decades to complete the many cave maps I have drawn.

  • LocalFluff

    I heard there’s a skin for GIMP that makes its user interface look like that of Photoshop, for those used with that. There doesn’t seem to be any immaterial property rights that stop making software that function and look like existing software.

  • wodun

    Thanks Robert Zimmerman, I think I asked this one before. Been a while since I tried gimp, will have to try it again. I have mostly been using phone apps, snapseed and photo editor on android, to modify pictures, some of them work surprisingly well but have to do some tasks in one than others in another.

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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