Venus May Still Be Geologically Active
Radar images of the planet’s surface suggest large sections of its crust appear to have moved in the geologically recent past
As NASA and other space exploration outfits prepare to send missions to Venus, new research suggests that the hot, toxic planet is geologically active, reports Leah Crane for New Scientist.
Specifically, a new paper, published this week in the journal the Proceedings of the National Academy of Sciences, finds that the Venusian surface is at least partly made up of massive hunks of planetary crust that may still be bumping up against each other like huge pieces of pack ice floating atop a roiling sea.
This type of activity doesn’t constitute true plate tectonics, explains Robin George Andrews for the New York Times, because not all of Venus’ surface is covered by jostling plates of crust and those plates don’t appear to slide over or under one another as Earth’s do.
Venus’ 58 pieces of crust are called campi—“fields” in Latin—and they range in size from about the size of Ireland to Alaska, per the Times.
"We've identified a previously unrecognized pattern of tectonic deformation on Venus, one that is driven by interior motion just like on Earth," Paul Byrne, a planetary scientist at North Carolina State University and the study’s lead author, in a statement. "Although different from the tectonics we currently see on Earth, it is still evidence of interior motion being expressed at the planet's surface."
According to New Scientist, the interior heat driving the Venusian geologic activity appears similar to what researchers think Earth would have been like around 2.5 to 4 billion years ago, which could make it a useful tool for understanding the early Earth.
“If you can understand what Venus is like now, that might give us some insight into what Earth used to look like,” Byrne tells New Scientist.
The study’s findings are based on a new analysis of radar images of Venus’ surface captured by NASA’s Magellan mission. Those images revealed areas of the planet’s surface that were contorted in ways that suggested it was being stretched, twisted or pushed together by forces from below.
The team then plugged those observations and measurements of Venus’ gravity field into a computer model to generate geological scenarios that could have produced what they were seeing.
“These observations tell us that interior motion is driving surface deformation on Venus, in a similar way to what happens on Earth,” Byrne says in the statement. “Plate tectonics on Earth are driven by convection in the mantle. The mantle is hot or cold in different places, it moves, and some of that motion transfers to Earth’s surface in the form of plate movement.”
But are these campi still moving today? This is one of the many questions that NASA and the European Space Agency’s missions to Venus hope to answer, according to the Times.