Using archival radar data from NASA’s Magellan spacecraft, planetary researchers have identified a vast underground conduit beneath the surface in the Venusian region of Nyx Mons.
Magellan radar image of Venus displaying several pit chains and the identified skylight, marked as A, potentially providing access to the subsurface (i.e., empty void); the white arrow indicates the radar illumination direction. Image credit: NASA / Carrer et al., doi: 10.1038/s41467-026-68643-6.
Lava tubes are natural underground tunnels formed by volcanic activity.
They typically originate in basaltic lava flows, where low-viscosity lava is either entrenched and crusted over or inflated in-between preexisting lava layers
Beside Earth, evidence of lava tubes has been identified on other celestial bodies such as Mars and the Moon.
For example, recent research provides compelling evidence of a subsurface cave conduit beneath the Mare Tranquillitatis Pit on the Moon.
The existence of lava tubes on Venus has been largely hypothesized but never confirmed.
“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,” said University of Trento’s Professor Lorenzo Bruzzone.
“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.”
“This discovery contributes to a deeper understanding of the processes that have shaped Venus’ evolution and opens new perspectives for the study of the planet.”
In the study, Professor Bruzzone and his colleagues analyzed the radar images from the Synthetic Aperture Radar, an instrument that mapped the surface of Venus aboard NASA’s Magellan spacecraft between 1990 and 1992.
“We analyzed Magellan’s radar images where there are signs of localized surface collapses using an imaging technique that we have developed to detect and characterize underground conduits near skylights,”
“Our analyses revealed the existence of a large subsurface conduit in the region of Nyx Mons, the area named after the Greek goddess of the night.”
This feature is characterized by a diameter of about 1 km (3,280 feet), a roof thickness of at least 150 m (492 feet) and an empty void height of no less than 375 m (1,230 feet).
The conduit extends in the subsurface for at least 300 m (984 feet) from the skylight.
“The available data allow us to confirm and measure only the portion of the cavity close to the skylight,” Professor Bruzzone said.
“However, analysis of the morphology and elevation of the surrounding terrain, together with the presence of other pits similar with the one studied, supports the hypothesis that the subsurface conduits may extend for at least 45 km (28 miles).”
“To test this hypothesis and identify additional lava tubes, new higher-resolution images and data acquired by radar systems capable of penetrating the surface will be required.”
“The results of the study are therefore very important for future missions to Venus, such as ESA’s Envision and NASA’s Veritas spacecraft.”
“Both spacecraft will carry advanced radar systems capable of capturing higher-resolution images, allowing scientists to study small surface pits in greater detail.”
“In addition, Envision will carry an orbital ground penetrating radar (Subsurface Radar Sounder) capable of probing Venus’ subsurface to depths of several hundred meters and potentially detecting conduits even in the absence of surface openings.”
“Our discovery therefore represents only the beginning of a long and fascinating research activity.”
The study was published today in the journal Nature Communications.
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L. Carrer et al. 2026. Radar-based observation of a lava tube on Venus. Nat Commun 17, 1147; doi: 10.1038/s41467-026-68643-6
