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.
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.
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