On Earth, lava tubes are the byproduct of volcanic activity that is left behind as liquid lava retreats, and are believed to exist on the Moon and Mars as well. “Our results suggest that lava tubes with widths of a few hundred meters may remain stable, and these dimensions are consistent with observed Venusian channel sizes,” the paper reads. A study last year similarly concluded that lava tubes could indeed exist on the planet. An additional mission, dubbed Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy (VERITAS), was designed to scan the planet’s surface with high-resolution near-infrared and radar instruments. More on the lava tubes: Scientists Confirm Massive Underground Tunnels on Venus