Venus may have an underground tunnel carved by volcano eruptions, according to scientists analyzing decades-old data from NASA's Magellan mission. If confirmed, this structure would be the second known lava tube on Venus, joining similar discoveries on the Moon and Mars. Lorenzo Bruzzone, a study co-author from the University of Trento in Italy, emphasizes the significance of this finding, stating, '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.' The identification of a volcanic cavity is crucial as it validates theories that have long hypothesized their existence. Venus is perpetually shrouded in dense clouds, making direct observation of its surface impossible. Scientists rely on radar imagery to study the planet's geology, and the Magellan orbiter mapped much of Venus' surface between 1990 and 1992, producing a vast archive of images that researchers continue to analyze. Magellan's radar mapped Venus by transmitting radio waves and measuring the time it took for the signals to bounce back, revealing long chains of pits or collapsed areas on the surface, hinting at the presence of underground lava tubes. The new study focuses on localized surface collapses, creating skylight-like openings that can expose underground voids. One such feature, located on the western flank of Nyx Mons, a major volcano on Venus, produced a distinctive radar pattern matching signatures known to arise from collapsed lava tube roofs. Analysis suggests the conduit could extend for a few dozen kilometers underground, but only part of the structure can be confirmed. Bruzzone highlights the need for new observations to confirm the full size, shape, and stability of the structure. Upcoming missions to Venus are expected to carry advanced radar instruments capable of capturing higher-resolution images, with a primary goal of studying subsurface cavities. The Subsurface Radar Sounder, or SRS, planned for the EnVision mission by the European Space Agency, can penetrate the planet's surface to depths of several hundred meters, potentially detecting conduits even in the absence of surface openings. Bruzzone concludes that this discovery marks the beginning of a long and fascinating research activity, with the findings detailed in a paper published in the journal Nature Communications.
