Leaving Earth cover

In 2019 I obtained from my former publisher the last 30 copies of the now out-of-print hardback of Leaving Earth. I sold about half of these, and with only a handful left in stock I have raised the price. To get your own autographed copy of this rare collector's item please send a $75 check (includes $5 shipping) payable to Robert Zimmerman to

Behind The Black, c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652

I will likely raise the price again when only ten books are left, so buy them now at this price while you still can!

Also available as an inexpensive ebook!

Leaving Earth: Space Stations, Rival Superpowers, and the Quest for Interplanetary Travel, can be purchased as an ebook everywhere for only $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from my ebook publisher, ebookit.


Winner of the 2003 Eugene M. Emme Award of the American Astronautical Society.

"Leaving Earth is one of the best and certainly the most comprehensive summary of our drive into space that I have ever read. It will be invaluable to future scholars because it will tell them how the next chapter of human history opened." -- Arthur C. Clarke

“Flow-like” feature in the Martian lowlands

Click for full image.

Cool image time! The photo to the right, rotated, cropped, reduced, and brightness-enhanced to post here, was taken on July 6, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

This is an uncaptioned image, labeled by the MRO science team as a “Flow-Like Feature in Chryse Planitia,” suggesting that they themselves are not exactly sure about what we are looking at. The latitude is 19 degrees north, which is a bit too far south for finding glacial features. Moreover, the craggy look of the ground here does not suggest an eroding glacier, but of eroding bedrock.

We could be looking at a volcanic feature, but this location is very far from Mars’ volcano regions. Nonetheless, another high resolution image, taken just to the west of this photo and given the exact same label, shows similar geology, and does strongly invoke a look of corroded lava flow.

The overview map below gives the context.

Overview map

Chryse Planitia is the lowland northern plain that received the drainage down from the giant Martian volcanoes, coming from both Valles Marineris and Kasei Valles. It is also the place that two American landers put down, Viking 1 in 1976 and Pathfinder in 1997. In fact, this image, indicated by the white box, is only about 108 miles west of the Mars Pathfinder landing site where the rover Sojourner roved for almost three months. The photo below shows Sojourner up against a boulder, the image taken from Pathfinder. The ramp that the rover used to get to the surface can be seen on the bottom left.

Sojourner rover on Mars, as seen from Mars Pathfinder

The results from Pathfinder and Sojourner suggested the presence of melted ejecta from impacts, melt from volcanic processes, and sedimentary and rounded rocks suggesting water processes.

None of this of course clarifies the flow feature in the cool image above, as all these process could have created this feature. It only adds to the mystery.

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.


  • Rod

    I don’t know why 19 degrees south would be too close to the equator. According to theory, Mars’ inclination varies wildly over the eons. Suppose, a billion years ago, the tilt was 70 degrees, and we could consider 19 degrees south to have near polar conditions. Just a thought.

  • Rod: I think you are new here. Do a search on Behind the Black for glaciers and Mars. You will learn a lot.

    Start however here: The glaciers of Mars. At this moment, scientists have found glacial features in large numbers in the latitude bands from 30 to 60 degrees. Farther south the evidence of water ice peters out, though not in every place.

    At 19 degrees it is unlikely this is glacial. Moreover, if you look at the many cool images that will come up in that search, you will begin to understand why this does not look like a glacier to me. The features aren’t the same as seen in the many other examples.

    However, you are right about Mars’ inclination, or obliquity as the scientists have told me is the correct term. It changes a lot over eons, from 11 degrees to 60 degrees. Today it is about 25 degrees. Things would have been very different when that obliquity was different. Once again, read some of those other links for info on what is presently believed.

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