by P. Voosen, Mar 15, 2023 in Science
Eruption spotted in 30-year-old data from Magellan mission
Choked by a smog of sulfuric acid and scorched by temperatures hot enough to melt lead, the surface of Venus is sure to be lifeless. For decades, researchers also thought the planet itself was dead, capped by a thick, stagnant lid of crust and unaltered by active rifts or volcanoes. But hints of volcanism have mounted recently, and now comes the best one yet: direct evidence for an eruption. Geologically, at least, Venus is alive.
The discovery comes from NASA’s Magellan spacecraft, which orbited Venus some 30 years ago and used radar to peer through the thick clouds. Images made 8 months apart show a volcano’s circular mouth, or caldera, growing dramatically in a sudden collapse. On Earth, such collapses occur when magma that had supported the caldera vents or drains away, as happened during a 2018 eruption at Hawaii’s Kilauea volcano. “I’m totally tickled, as a geomorphologist, to see this,” says Martha Gilmore, a planetary scientist at Wesleyan University who was not involved in the study.
Witnessing this unrest during the short observation period suggests either Magellan was spectacularly lucky, or, like Earth, Venus has many volcanoes spouting off regularly, says Robert Herrick, a planetary scientist at the University of Alaska, Fairbanks. Herrick, who led the study, says, “We can rule out that it’s a dying planet.”