“Some of these answers are on Earth, but some of them are on Venus,” said Dr. Wilson.
EnVision will investigate these secrets using a range of advanced scientific tools. Its radar systems will peer through Venus’ dense atmosphere and map both the surface and the rock layers up to 3,300 feet below the surface. A series of spectrometers that see in ultraviolet and infrared light will analyze the chemical composition of the atmosphere and differentiate between types of rock on the ground. A radio science experiment will be able to use slight changes in the planet’s gravity to analyze the stratified cake structure of the geological entrails of Venus.
All of these tools will help answer another important question. “Geologically speaking, is Venus alive or dead?” said Dr. Wilson. Venus, a world dominated by volcanoes and eruptive graffiti, clearly had a geologically hyperactive past. Although most scientists suspect that Venus is still erupting today, the thick cloud cover prevented confirmation of this idea, just as it prevented the search for the tell-tale earth-shaking movement of faults.
By conducting surgical scientific studies in certain parts of the planet, EnVision will be able to fully remove this uncertainty. It can detect the thermal signatures of active volcanoes, sniff the gas clouds of erupting volcanoes, and look for evidence of ongoing tectonic back and forth.
The spacecraft will also be able to peer into Venus’ past in search of the scar tissue left by ancient plate tectonics and the relics of its epic, primeval volcanic activity – the kind some suspect the runaway greenhouse effect who raised the planet. It will also examine the Tesserae, curious plateaus that rise above plains of younger lava. Some think that these could be deformed layers of continental-like rock. If so, it means they formed in the presence of liquid water – further evidence that Venus was once an ocean world.
As capable as these three missions are, they will not solve all of Venus’ mysteries, such as whether phosphine, a gas that may be present in the planet’s clouds, is made by microbial life.
But the hope is that this is the beginning of a second Venus renaissance. “It sets the stage for sustainable Venus exploration,” said Dr. Byrne, and just a longer string of missions to Venus – from more orbiters and probes to atmospheric balloons and landers – will let us discover why she became Earth’s evil twin.