Scientists baked volcanic minerals in a box furnace to model how quickly lava ages on the planet’s harsh surface
Maat Mons, Venus' highest volcano, one of several that may still be active in present day (Public domain)
By Katherine J. Wu
January 6, 2020 1:17PM
Searing hot, bone dry and cloaked in clouds of acid, Venus is hardly a haven of habitability. Like Earth, however, Venus may still harbor active volcanoes, suggests a study published last week in Science Advances. Though this idea has been proposed before, new evidence hints that the lava flows that ripple across the planet’s scorched surface may be just a few years old, bolstering the case for recent eruptions.
Researchers have known for decades that Venus’ surface is mottled with volcanoes, but determining whether those volcanoes are dormant or active from a distance is tricky. Using data collected from the European Space Agency’s now-dead orbiter, Venus Express, scientists have found several hints of residual volcanic activity in the planet’s atmosphere, including hotspots of searing heat and blips of sulfur dioxide, the gassy calling card of active volcanoes here on Earth.
“If Venus is indeed active today, it would make a great place to visit to better understand the interiors of planets,” study author Justin Filiberto, a staff scientist at the Lunar and Planetary Institute’s Universities Space Research Association, says in a statement.
The spacecraft has also snapped images of young-looking lava flows, full of minerals not yet chemically corrupted from exposure to the planet’s harsh exterior. Depending on local conditions, rocks can take up to 2.5 million years to show signs of erosion. Without more information on how rocks evolve on Venus’ hellish surface, scientists couldn’t put a more exact number on the lava’s age.
So Filiberto and his team recreated the planet’s sweltering atmosphere in the lab with a box furnace that could burn at more than 1,000 degrees Fahrenheit—a few ticks above Venus’ average of 860 degrees Fahrenheit. The researchers then watched how crystals of olivine, a mineral commonly found in volcanic rock, aged and weathered when exposed to these extremes for days or weeks at a time.
Because olivine contains iron, it’s prone to rusting, a process that coats the normally greenish mineral in a reddish-black hue. The change constitutes a rough proxy for old age, and makes the olivine more difficult to detect with an orbiting spacecraft. In the box furnace, the olivine rusted in just a matter of days—the equivalent of months or years on Venus, the team’s models suggest. Since spacecraft have spotted olivine on Venus as recently as 2014, Choi reports, fresh lava has likely been belched onto the planet’s surface within the last few decades.
At the end of the day, though, a box furnace is just a box furnace, especially when circulating normal Earth air. To verify their results, Filiberto and his colleagues are repeating their experiments with other minerals baked with more Venus-like air that’s pumped full of carbon dioxide and sulfur, Choi reports. So far, Filiberto tells Choi, the early data are promising.
The real clincher, of course, will have to come from Venus itself. Future missions to the planet, Filiberto says in the statement, “should be able to see these [young lava] flows and changes in the surface and provide concrete evidence of its activity.”