Scientists analyzing decades-old data from NASA’s Magellan mission say they have identified what appears to be a vast underground tunnel carved by volcanic activity on Venus. The feature, a potential lava tube, was discovered in the Nyx Mons region of the planet.
If confirmed, this would be only the second reported lava tube on Venus, adding to similar discoveries on the Moon, and Mars. The finding contributes to a growing body of evidence challenging the long-held view of Venus as a geologically inactive world.
Lava tubes are formed when the surface of a lava flow cools and hardens, while the molten lava continues to flow beneath, eventually draining away and leaving a hollow tunnel. On Earth, these structures offer protection from radiation and extreme temperatures, and have become a subject of interest for potential habitats on other planets.
“Our knowledge of Venus is still limited, and until now we have never had the opportunity to directly observe processes occurring beneath the surface of Earth’s twin planet,” study co-author Lorenzo Bruzzone of the University of Trento in Italy said in a statement. “The identification of a volcanic cavity is therefore of particular importance, as it allows us to validate theories that for many years have only hypothesized their existence.”
Venus presents a significant challenge to surface observation due to its perpetually dense cloud cover. Scientists rely heavily on radar imagery to study the planet’s geology. NASA’s Magellan orbiter, which mapped much of Venus’ surface between and , provided the data used in this latest analysis. The orbiter utilized a Synthetic Aperture Radar (SAR) system to penetrate the clouds and create detailed surface maps.
The researchers focused on areas exhibiting localized surface collapses, known as skylights, which indicate the presence of voids beneath the surface. The identified structure, located on the western flank of Nyx Mons, displayed a radar signature consistent with a collapsed lava tube roof. Analysis suggests the conduit extends for at least 300 meters from the skylight, with a diameter of approximately 1 kilometer, a roof thickness of at least 150 meters, and an empty void height of no less than 375 meters.
The team leveraged a SAR imaging technique originally developed for detecting subsurface conduits near skylights. This technique allowed them to analyze Magellan radar images and identify the potential lava tube.
The discovery is particularly significant given the extreme conditions on Venus. The planet’s surface temperatures exceed 900 degrees Fahrenheit, and its atmospheric pressure is nearly 100 times that of Earth. Lava tubes could potentially offer a shielded environment, protecting future research outposts from these harsh conditions and providing radiation shielding.
Further investigation is needed to confirm the full extent and stability of the structure. Fortunately, a new generation of Venus missions is on the horizon. These missions are expected to carry more advanced radar instruments capable of higher-resolution imaging and subsurface probing. The European Space Agency’s EnVision mission, for example, includes a Subsurface Radar Sounder (SRS) designed to penetrate the planet’s surface to depths of several hundred meters.
“The SRS is capable of ‘probing Venus’s subsurface to depths of several hundred meters and potentially detecting conduits even in the absence of surface openings,'” Bruzzone said. “Our discovery therefore represents only the beginning of a long and fascinating research activity.”
This research was published on in the journal Nature Communications.
