Venus Is Hiding A Massive Underground Tunnel Carved By Ancient Volcanoes

by Aaron Leong — Tuesday, February 10, 2026, 10:51 AM EDT

Scientists at the University of Trento have uncovered the first direct evidence of a subsurface feature beneath Venus: a massive underground lava tube on the most volcanically active planet in the Solar System.

Published this week in the Nature journal, the finding was actually made by re-analyzing archival radar data from NASA’s Magellan mission, which mapped the Venusian surface in the early 1990s. Using a recently-developed data-analysis technique, the team identified a "skylight," or rather, a collapsed section of a cave roof, on the western flank of Nyx Mons, a giant shield volcano in the northern hemisphere. This opening acts as a window into a large void that appears to be an empty volcanic conduit, or pyroduct.

This Venusian tunnel is pretty gargantuan, dwarfing almost any similar structure found on Earth. According to the data, the cavity measures approximately 0.6 miles (1 kilometer) in diameter, with a protective rock ceiling at least 490 feet (150 meters) thick and an internal void reaching depths of 0.75 mi (375 m). To put that in perspective, this single tunnel is large enough to house multiple city skyscrapers with room to spare. On Earth, gravity usually causes such massive hollow structures to collapse, but Venus’s specific environmental conditions, such as high atmospheric pressure and lower gravity, may allow these subterranean giants to remain stable. The study figures that this particular tube could snake through the subsurface for at least 28 mi (45 km), potentially forming part of one of the most extensive volcanic networks in the Solar System.

The existence of these tubes may prove that the planet was once, and perhaps still is, capable of sustaining complex volcanic plumbing systems similar to those on the Moon and Mars. While the surface of Venus remains a hellscape with temperatures around 869 °F 465 °C and crushing pressure, these underground chambers offer a glimpse into a more shielded environment. Perhaps one day they could provide a natural refuge for robotic explorers, protecting them from the extreme heat and sulfuric acid rain.

It's quite possible that these finding will reshape the objectives of the upcoming ESA’s EnVision and NASA’s VERITAS missions, which are slated to carry subsurface radar sounders. These instruments will be capable of peering hundreds of meters into the ground, potentially uncovering thousands more miles of hidden tunnels.