I BLAME VENUSIAN SUV DRIVERS: “Venus may have been a temperate planet hosting liquid water for 2-3 billion years, until a dramatic transformation starting over 700 million years ago resurfaced around 80% of the planet.”
Forty years ago, NASA’s Pioneer Venus mission found tantalising hints that Earth’s ‘twisted sister’ planet may once have had a shallow ocean’s worth of water. To see if Venus might ever have had a stable climate capable of supporting liquid water, Dr. Way and his colleague, Anthony Del Genio, have created a series of five simulations assuming different levels of water coverage.
In all five scenarios, they found that Venus was able to maintain stable temperatures between a maximum of about 50 degrees Celsius and a minimum of about 20 degrees Celsius for around three billion years. A temperate climate might even have been maintained on Venus today had there not been a series of events that caused a release, or ‘outgassing’, of carbon dioxide stored in the rocks of the planet approximately 700-750 million years ago.
“Our hypothesis is that Venus may have had a stable climate for billions of years. It is possible that the near-global resurfacing event is responsible for its transformation from an Earth-like climate to the hellish hot-house we see today,” said Way.
So the watery, tropical Venus of 1950s SF wasn’t wrong, just . . . out of date.