The cave was discovered thanks to a new look at data from the 1990s from an orbiting radar.
Hidden from the view of astronomers by dense clouds, Earth’s “sister planet”, Venus, is gradually revealing some of its secrets.
A lava tube beneath the Venusian surface – the first ever detected – could help explain how the planet formed, researchers report February 9 in Natural communications. The detection was made by re-analyzing orbital radar data from a NASA probe from the early 1990s, to reveal a collapsed “skylight” in the roof of the lava tube.
This discovery will influence two future probes: that of NASA VERITAS mission, scheduled to launch before June 2031, and the European Space Agency’s EnVision mission, scheduled to launch later the same year..
“Both spacecraft will carry advanced radar instruments capable of acquiring images of the surface of Venus with significantly higher resolution than those currently available,” says Lorenzo Bruzzone, a remote sensing scientist at the University of Trento in Italy.
Venus has been called Earth’s sister planet because it is relatively close and almost the same size. But the clouds perpetually hide it from view.
NASA’s Magellan probe revealed that the surface is shaped by active volcanoesalthough there is little sign that Venus ever had plate tectonics. The probe decades-old radar maps are still the best scientists, and Bruzzone and his colleagues reanalyzed the data with specialized imaging techniques to spot the telltale skylights.
Their search revealed a skylight near a massive shield volcano called Nyx Mons (“Mountain of Nyx” in Greek, named after an ancient goddess of the night.)
Further analysis revealed that the collapsed skylight was approximately 150 meters deep and opened into an empty lava tube at least 375 meters deep.
Lava tubes on the Moon could one day serve as shelters for astronauts from solar radiation and meteorites, and they have also been detected on Mars.But no humans are likely to visit the Nyx Mons lava tube on Venus, where the atmospheric pressure at the surface is 93 times thicker than that of Earth, and where it is so hot that ordinary silicon electronics won’t work.
Nevertheless, the discovery of the lava tube on Venus suggests that there are others, while validating certain patterns of volcanism on the mysterious planetsaid Bruzzone.
Planetary scientist Anna Gülcher of the University of Freiburg in Germany was not involved in the work, but is studying how volcanoes shape Venus.
“It is remarkable that we continue to extract new information from the Magellan data, collected more than thirty years ago,” says Gülcher.
“This highlights both the enduring value of this mission, the progress we have made in data analysis, and the renewed interest in the planet.”
