Venus: 80% of Its History Is Missing
In spite of being called Earth’s twin, Venus is vastly different. Scientists are struggling to fit its young surface to 4.5 billion years.
A land of global lava flows and volcanoes but few craters (for its assumed age), Venus has defied explanation for decades. Ideas about its origin and geological evolution have been overturned several times since the first spacecraft visited it in the 1970s. The Magellan mapping mission (19xx-19xx) did the most to startle scientists who expected to find its geology similar to Earth’s.
An open-access article in Geology by James Head tells the story of shifting paradigms about Venus. In a section called “The Conundrum of Venus,” he includes the single exclamation point of the article:
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.
Emphasizing the conundrum, he spoke again of “the missing ∼80% of Venus history.” That figure may be his own estimate; in The New Solar System, 4th ed. (1998), p.110, R. Stephen Saunders stated that volcanic resurfacing “seems to have run rampant over a short period of time, obscuring all traces of what had occurred during the first 90 percent or so of the planet’s history.” Whether 80% or 90%, this speaks of a long unknown history, a short period of violent volcanism, then quiet for the remaining few hundred million years or so, assuming conventional dating.
James Head describes the theorizing that has been ongoing since Magellan’s surprising results – a work in progress still. Better mapping has allowed solar system geologists to correlate some features into global regimes. The realization of an entire globe undergoing simultaneous catastrophic upheaval is leading some to ask whether such violent changes are possible on Earth. Many questions, however, still remain that will require a “renaissance in Venus science.”
The Renaissance was a “rebirth” of classical ideals, looking back at Greece and Rome as models for how to build a civilization. It was needed, Petrarch and other Renaissance humanists argued, because of centuries of medieval malaise that was making little progress in the arts, sciences and civics. Similarly, decades of Darwinism and Lyellism have led to intellectual laziness that struggles with contradictions between its assumptions and the observations. It will require a scientific renaissance greater than James Head calls for – a return to “classical” geology based on theism (in particular, Genesis) to take geology out of its dark ages and put it back in the framework that makes sense of the evidence.
James Head has just described planetary scientists wrestling with ideas outside their expectations: rapid, global catastrophism. Similar contradictions of secular predictions with observations apply to Mercury, Enceladus, Europa, Miranda, Earth, Vesta, comets, asteroids, and much more. The number of worlds in our solar system that have matched expectations is a minority of worlds spacecraft have visited. As for global catastrophism, have they never considered Noah’s flood, involving the world’s rift systems forming in a matter of weeks or months in the Biblical timeframe? Lyellism has already been falsified. Sometimes progress requires backtracking from a wrong turn, having the humility to realize that wisdom can be discovered before the poorly-named Enlightenment.