Mysterious features on the surface of Venus might suggest that there is activity under its surface, scientists have suggested.
Almost circular features on the surface might suggest that it has active tectonics, according to new research. Though the findings are new, the data used to discover them are actually more than 30 years old, originally found by Nasa’s Magellan mission.
The behaviour is similar to the tectonic plates found on Earth, which are huge sections of crust that move on top of a viscous interior and are constantly changing the surface. Venus doesn’t have tectonic plates, but researchers suggest that it is nonetheless being changed by molten material that is beneath the surface.
To understand the deformations in the surface, researchers looked at coronae that are found on Venus. They can be anywhere from dozens to hundreds of miles across, there are hundreds of them on the planet, and they are thought to be formed when material rises from the planet’s mantle and pushes against the crust above.
The findings not only shed light on the nearby planet but might also tell us about the history of Earth.
“Coronae are not found on Earth today; however, they may have existed when our planet was young and before plate tectonics had been established,” said the study’s lead author, Gael Cascioli, assistant research scientist at the University of Maryland, Baltimore County, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “By combining gravity and topography data, this research has provided a new and important insight into the possible subsurface processes currently shaping the surface of Venus.”
The data was gathered by the Magellan mission, which remains the best data on the gravity and topography of Venus despite having orbited the planet in the 1990s. That data includes details on the coronae, but at the time it was taken the cause of them remained mysterious.
Researchers have proposed a number of explanations for them. But the new research involved creating detailed models that looked at what would happen if the coronae were formed by plumes from underneath – and then compared those simulations with the real data from the planet.
They appeared to match up. Researchers found that of the 75 coronae in the study, 52 of them appeared to have floating mantle material underneath that is probably affecting the surface.
Scientists hope that the Magellan data could soon be joined by Nasa’s VERITAS mission, which will launch no earlier than 2031 and will provide new detail on the planet’s gravity and other details. That could not only help understand those coronae but its geology more generally.
The new work is reported in a paper, ‘A spectrum of tectonic processes at coronae on Venus revealed by gravity and topography’, published in the journal Science Advances.
