Scientists analyzing radar data from NASA’s 1990–1992 Magellan mission say they’ve identified a possible underground lava tube on Venus, a discovery that would be only the second such structure found on the planet.

The feature, located on the western flank of Nyx Mons, appears to extend for several dozen kilometers and may have formed through volcanic activity.

This finding challenges the long-held belief that Venus is geologically inactive and supports theories about subsurface processes previously unobservable.

Radar patterns from surface collapses, or “skylights,” helped researchers infer the presence of the underground conduit, Space.com has reported.

Future missions, including ESA’s EnVision with its Subsurface Radar Sounder, could confirm the tube’s full size, shape, and stability, potentially revealing more hidden features beneath Venus’s surface.