Present-day volcanism on Venus might be far more pervasive than previously believed.
A new analysis of decades-old data from NASA’s Magellan spacecraft finds signs of fresh lava flows occurring on the Venusian surface between 1990 and 1992, researchers report May 27 in Nature Astronomy.
“This definitely is another step in the path to understanding Venus as a living, breathing world,” says planetary scientist Paul Byrne of Washington University in St. Louis, who was not involved in the work.
Despite being nearly the same size as our own planet, Venus was for a long time considered geologically dead. Still, many scientists suspected that Earth’s near twin should have comparable levels of internal heat, the main driver of things like volcanoes and quakes.
Last year, a team announced that they had spotted a volcanic vent changing shape and potentially spilling out lava in Magellan data, the first definitive evidence of such activity on our hellish sister world (SN: 3/15/23).
The new work follows a similar path, hunting across Venus’ extensive surface — three times the area of dry land on Earth — for signs of volcanism. On the western slopes of Sif Mons, a large shield volcano, and Niobe Planitia, a flat region studded with volcanic vents, Magellan’s radar images showed long sinuous features appearing between two of the spacecraft’s passes over the planet.
Planetary scientist David Sulcanese of D’Annunzio University in Chieti-Pescara, Italy, and his colleagues considered the possibility that these were artifacts in the radar data or the result of things like landslides. The features followed the local topography, suggesting they were really spilling across Venus’ surface, and occurred in fairly flat areas where landslides wouldn’t be expected, the researchers argue.
“They were able to show, I think convincingly, that in these two instances the changes in how the surface looks in radar is best explained by there being lava flows,” Byrne says.
The relatively low resolution of Magellan’s data and Venus’ enormous land area means that it took painstaking effort to uncover these few signs of active volcanism. But Byrne suspects they’re not the only ones. “If you had an army of people day in and day out looking through the entire surface, there’s likely much more to be found,” he says.
Both he and the study authors agree that Venus could currently have as much volcanic activity as Earth. NASA’s DAVINCI and VERITAS probes, expected to launch next decade, will map the Venusian surface in far more detail, making it easier to spot such signs.
