The geological history of Venus: What’s known, not known, and unknown.

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.

The geological history of Venus: What’s known, not known, and unknown.

This is a very clearly written overview by James Head, one of the world’s preeminent planetary geologists, of what has been learned about the geology of Earth’s sister planet, the planet of a million volcanoes. Key quote:

Many features on Venus (folded mountain belts, rift zones, tesserae) were like Earth, but there were few signs of Earth-like plate tectonics, so that Venus seemed to have a single lithospheric plate that was losing heat conductively and advectively. But the cratering record presented a conundrum. First, the average age of the surface was <20% of the total age of the planet, and second, the average was not a combination of very old and very young surfaces, such as Earth’s continents and ocean basins. Third, the lack of variability in crater density, and of a spectrum of crater degradation, meant that all geological units might be about the same age. This implied that the observed surface of Venus must have been produced in the past hundreds of millions of years, possibly catastrophically, with very little volcanic or tectonic resurfacing since then! Suddenly, Venus was not like Earth, nor like the Moon, Mars, or Mercury.

Some scientists even believe that Venus was essentially resurfaced in a massive volcanic event about a half billion years ago. Others disagree. Meanwhile, the European probe Venus Express has gotten hints that volcanic activity is still going on.

As Head concludes, it has been 20 years since the last spacecraft arrived at Venus to do geological research. It is time to return.


Every July, to celebrate the anniversary of the start of Behind the Black in 2010, I hold a month-long fund-raising campaign to make it possible for me to continue my work here for another year.

This year's fund-raising drive however is more significant in that it is also the 10th anniversary of this website's founding. It is hard to believe, but I have been doing this for a full decade, during which I have written more than 22,000 posts, of which more than 1,000 were essays and almost 2,600 were evening pauses.

This year's fund drive is also more important because of the growing intolerance of free speech and dissent in American culture. Increasingly people who don't like what they read are blatantly acting to blackball sites like mine. I have tried to insulate myself from this tyrannical effort by not depending on Google advertising or cross-posts Facebook or Twitter. Though this prevents them from having a hold on me, it also acts to limit my exposure.

Therefore, I hope you will please consider donating to Behind the Black, by giving either a one-time contribution or a regular subscription, as outlined in the tip jar below. 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.


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
P.O.Box 1262
Cortaro, AZ 85652


  • So not much as changed since Magellan. Which I guess isn’t surprising. Nova did a great special in the 90’s about Magellan’s work this makes it sound like its still mostly current.

    Sadly considering the track record for probes making it to the surface of Venus its unlikely anyone is going to front the money anytime soon for something to get crushed or get 20 minutes of data for a billion bucks.

  • Just to set the record straight, the last five Soviet Venus landers, Venera 10 through 14, all operated for more than hour on the surface, with the average generally closer to two hours. Venera 13 for example operated for more than 2 hours.The two probes before that all operated for more than 50 minutes, while Venera 7, the first to successfully send back data, operated for 23 minutes. See The Chronological Encyclopedia of Discoveries in Space, pages 92, 106, 136, 161, 162, 182, 183.

    Granted, the cost was high for so little operating time, but considering the hostile Venus surface environment these missions were hardly failures, they were engineering achievements of the first order.

  • wodun

    Why go to the surface? It might be more worthwhile to have some bots higher up in the atmosphere.

  • You learn a lot by working the atmosphere. In fact, it’s already been done by two French balloons that floated in the atmosphere for two days back in 1985. Nonetheless, to study the geology you have to go down to the ground and sample it, like the rovers on Mars are doing.

  • D. K. Williams

    ‘I would give Venus a very low priority for funding. It’s a very nasty place. A Martian probe may last for years, and we may send people there someday. Not so our sister planet, unfortunately.

  • Edward

    It may not be a place that we will go to, but as we explore the universe and look for other habitable planets, it is always good to know what kinds of planets there are, how they formed, and whether we could one day teraform them. It may be too early to prosper from all the answers that we can get from Venus, so the return on investment is lower than other explorations, but the answers are good to know, as they help us fill in pieces of the puzzle that is the universe.

    Some day we may figure out how to build a rover for Venus that will last a decade.

Leave a Reply

Your email address will not be published. Required fields are marked *