Conscious Choice cover

From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.

Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.  
Conscious Choice does more however. In telling the tragic history of the Virginia colony and the rise of slavery there, Zimmerman lays out the proper path for creating healthy societies in places like the Moon and Mars.


“Zimmerman’s ground-breaking history provides every future generation the basic framework for establishing new societies on other worlds. We would be wise to heed what he says.” —Robert Zubrin, founder of founder of the Mars Society.


Available everywhere for $3.99 (before discount) at Amazon, Barnes & Noble, and all ebook vendors, or direct from the ebook publisher, ebookit. And if you buy it from ebookit you don't support the big tech companies and I get a bigger cut much sooner.

Martian impact into lava crust?

Impact crater north of Pavonis Mons
Click for full image.

Cool image time! The photo on the right, cropped to post here, was taken by the high resolution camera on April 23, 2019. It shows a quite intriguing impact crater on the northern lava slopes of Pavonis Mons, the middle volcano in the chain of three gigantic volcanoes to the west of Valles Marineris.

What makes this image cool is what the impact did when it hit. Note the circular depression just outside the crater’s rim. In the southeast quadrant that ring also includes a number of additional parallel and concentric depressions. Beyond the depression ground appears mottled, almost like splashed mud.

What could have caused this circular depression? Our first clue comes from the crater’s location, as shown in the overview map below and to the right.

Pavonis Mons

The white box indicates the location of this crater north of Pavonis Mons. From this overview, it appears that the bolide landed on a giant lava flow that to my eye was seeping out of the base of the volcano’s steeper flanks. This flow also appears to be younger than the surrounding terrain, as it seems to have overlaid and filled ground that would have been similar to the rough parallel cracks to its immediate east.

My guess is that the impact that formed this crater occurred during or near the end of this colossal lava flow. The surface had solidified into a hard and somewhat thick crust, with still hot and molten lava below. When the bolide hit it cracked the crust, but because the crust was thick it did not break into many pieces with many cracks, but instead broke in one piece, a disk that was pushed downward into the softer molten lava below. Think of a bullet hitting a bullet-proof material, as in these two examples here and here.

The disk and crater are not lower than the surrounding terrain because after hitting that liquid lava layer below they would have rebounded. The impact however pushed that lava below outward to form the radiating skirt beyond the circular depression.

It is also possible that the impact hit after the lava was solid, but with two layers of different structural strengths. The top layer was stronger, and broke in the manner I just described. The lower level in turn was melted by the heat of impact, and then produced the features as outlined.

All a guess on my part, as an amateur geologist with only a dangerous smattering of knowledge of Earth-based geology. On Mars, in its lighter gravity with different chemistries, things could be very different. Either way, the feature suggests that the lower layers here were either less dense, more porous, or had voids. All intriguing possibilities.

One last detail: The parallel ridges inside the crater are probably dunes, as craters on Mars tend to be sand traps, capturing dust over time. The wind then reshapes them into dunes, but the dust has trouble escaping so it begins to pile up.

Or not. There appears to be a break in the crater’s north rim where these ridges are largest and most pronounced. Maybe instead these ridges represent some sort of lava flow, related to that break. The image’s resolution is not good enough to clarify this, so your guess is as good as mine.


I must unfortunately ask you for your financial support because I do not depend on ads and rely entirely on the generosity of readers to keep Behind the Black running. You can either make a one time donation for whatever amount you wish, or you sign up for a monthly subscription ranging from $2 to $15 through Paypal or $3 to $50 through Patreon.

Your support will allow me to continue covering science and culture as I have for the past twenty years, independent and free from any outside influence.

Your support is even more essential to me because I not only keep this site free from advertisements, I do not use the corrupt social media companies like Google, Twitter, and Facebook to promote my work. I depend wholly on the direct support of my readers.

You can provide that support to Behind The Black with a contribution via Patreon or PayPal. To use Patreon, go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation. For PayPal click one of the following buttons:


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


If Patreon or Paypal don'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

Or you can donate by using Zelle through your bank. You will need to give my name and email address (found at the bottom of the "About" page). The best part of this electronic option is that no fees will be deducted! What you donate will be what I receive.


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 *