New research adds to the increasing body of evidence that Venus is volcanically active – a conclusion that, if confirmed, would help explain how volcanoes influence planetary development and habitability throughout the universe. The study, which focuses on odd signals originating from a Venusian volcano named Idunn Mons, is stoking interest in future expeditions to Earth’s nearest neighbor that will finally resolve the subject.
It’s long been known that Venus is covered in bizarre volcanoes. However, it is hard to know whether they are still pouring lava from Earth since Venus’s thick and murky atmosphere obscures whatever is going on on the ground.
A team of scientists is now claiming that the 1.5-mile high, 125-mile wide Idunn Mons has been active within the last few thousand years, and is likely still erupting today, based on archive views from ancient orbiter missions and the findings of experimental work undertaken on Earth. They won’t have to wait long to get confirmation of their suspicions: a small squadron of spacecraft capable of detecting volcanic activity on Venus will launch within the next decade.
At this point, Justin Filiberto, branch chief in NASA Johnson Space Center’s Astromaterials Research and Exploration Science (ARES) Research Office and co-author of the study published last month in The Planetary Science Journal, doesn’t think “anyone would be surprised” if “we got to Venus, we’d find evidence of volcanic activity.”
Nonetheless, confirmation of that suspicion would have far-reaching consequences. Venus, like Earth, formerly contained an ocean’s worth of water, but it is now a barren wasteland with a thick, acidic atmosphere and a surface hot enough to melt lead. Epic volcanic eruptions that triggered permanent climatic change are one of the primary explanations for Venus’s horrific makeover. Close examination of Venus’s volcanoes will help us comprehend why Earth has not (yet) experienced a comparable eruptive disaster. While dead volcanoes may provide some hints, volcanoes are far simpler to understand if you can see them in motion.
While there is no direct evidence of ongoing volcanism on Venus, there are a few hints. If volcanoes are still ejecting sulfur dioxide, a common volcanic gas, the high concentration in Venus’s atmosphere makes a lot more sense. Tectonic rift zones — centers of volcanic activity on Earth – can be found on Venus’s surface, as well as cauldron-like volcanic features that are occasionally sculpted in a way that suggests they are being modified by underlying heat. To put it another way, it would be strange if Venus was volcanically dead due to its immense size. “Venus is the same size as Earth. Earth isn’t volcanically dead, so why would we expect Venus to be?” says Lauren Jozwiak, a planetary volcanologist at Johns Hopkins University’s Applied Physical Laboratory.
The new study combines a variety of data to imply that Idunn Mons’ magmatic heart is still beating today.
The Venus Express mission, which circled the planet from 2006 to 2014, discovered blazing infrared lava flow deposits all around the planet, notably at Idunn Mons. The corrosive atmosphere of Venus swiftly eats up volcanic materials, reducing their infrared light. As a result, the high thermal emissions were considered to be caused by lavas that erupted as recently as 250,000 years ago. However, new experimental work in which volcanic materials were roasted under Venusian atmospheric conditions and decayed quicker than previously assumed suggests that the lavas erupted within the last 1,000 years. And, in Idunn Mons, in particular, winds are being affected to a greater extent than would be predicted given the volcano’s geography. According to the authors, heat from molten rocks may be contributing to the turbulence above the volcano.
Jozwiak, who was not engaged in the research, describes it as “very convincing casework.” Future satellite trips to Venus, such as NASA’s VERITAS and DAVINCI+ missions, as well as Europe’s EnVision probe, which are scheduled to launch near the end of this decade, will validate its concerns.
The VERITAS mission is equipped with cutting-edge radar equipment that will be able to detect fresh lava without a doubt. It will fly over the same areas that an earlier radar-equipped spacecraft known as Magellan surveyed. If a lava flow appears that did not exist when Magellan visited Venus in the early 1990s, VERITAS will locate it. During its journey around the planet, NASA’s intrepid spacecraft may potentially find new lava flows. The infrared camera on the VERITAS will also make it easier to locate young lava flows that are still releasing heat.
While VERITAS studies large areas of the planet, Europe’s EnVision orbiter conducts surgical scientific strikes. Its radar system will seek for recent traces of volcanic or tectonic terraforming on the ground, and its infrared and ultraviolet spectrometers will hunt for strange chemical mixtures in the sky and on the ground. It will know if the spacecraft concentrates on a volcano that is spouting lava or poisonous gases, or on a tranquil volcano whose magma is radiating heat from under the surface.
DAVINCI+ (Deep Atmosphere Venus Investigation of Noble Gases, Chemistry, and Imaging Plus) will send a probe into Venus’s atmosphere to study the planet’s chemistry before crashing on the planet’s surface. Scientists working with VERITAS and EnVision will be able to more quickly recognize spikes in the quantities of those gases, indicating that a recent eruption has topped them up, with DAVINCI+ giving a profile of the volcanic gases present then.
Many planetary scientists believe that proving Venus’s volcanic activity is a formality at this time. “It would be truly astonishing if it wasn’t,” says Richard Ghail, a planetary geologist at the Royal Holloway University of London and EnVision’s lead scientist. Paul Byrne, a planetary scientist at Washington University in St. Louis, agrees. “The likelihood of there being no active volcanism on Venus must be functionally zero,” says Byrne.
Future missions to Venus will be intriguing for Ghail and others because of what they will be able to teach us about how active it is. Is it more like Earth, where dozens of eruptions occur every day, or Mars, a volcanically dormant globe where massive cascades of molten rock could flood the surface every few million years? Some predict Venus will erupt to its rhythm, while others believe it will be closer to Earth’s. These three prospective missions will soon find out, putting decades of volcanic speculation to rest.
“I think we’re going to be writing brand new textbooks about Venus once all of these missions get there,” says Filiberto. “It’s going to change how we think about planetary evolution.”
