We’ve known for quite some time that molten rock gouged enormous tunnels into the surface of the Earth, the Moon, and Mars.
In fact, scientists have proposed that the vast lava tubes under the surface of the Moon and Mars could one day serve as homes for space colonists that provide shelter from space radiation and micrometeorite strikes.
Now, as New Scientist reports, researchers have confirmed that lava tubes also exist on Venus, our closest — and hellishly hot — planetary neighbor.
Surprisingly, the subterranean tunnels appear to have a lot more in common with those found on the Moon than on Earth.
It’s an unexpected finding, since Venus’ mass and gravity are more similar to the Earth than the Moon. Scientists have previously found that lava tubes tend to be larger when there’s less gravity, since their walls are less likely to collapse.
“Earth lava tubes have smaller volumes, Mars tubes have slightly bigger volumes, and then the Moon’s tubes have even bigger volumes,” said University of Padova researcher Barbara De Toffoli during the Europlanet Science Congress in Finland earlier this month, as quoted by New Scientist. “And then there’s Venus, completely disrupting this trend, displaying very, very big tube volumes.”
“This is already giving away the fact that there’s likely something more on Venus playing a significant role,” she added.
Over the years, astronomers have spotted holes and large pits dotting Venus’ surface, suggesting the existence of lava tubes. Until now, though, they were unable to rule out other geological processes that could’ve caused them.
Now, as detailed in a new paper, De Toffoli and her colleagues presented the “first compelling evidence for the existence of lava tubes on Venus.”
They found that they were not only arranged near large volcanoes, but that the pits “also develop in a direction consistent with the slope of the terrain on which they were observed, thus consistent with the hypothesis that they are the product of lava flowing on an inclined surface.”
The team modeled these cavities and found that they perfectly match the formation process that involves the “upper layer of a lava flow while the underlying molten lava continues to drain, leaving behind a hollow conduit.”
Venus’ extremely hot and high-pressure environment could allow these tubes to grow to very large sizes, despite being exposed to stronger gravitational forces than on the Moon. In fact, the possible volumes of these tubes caught the researchers off guard.
“The characteristics of the observed Venusian lava tubes, particularly their large scale, suggest that Venus may host some of the most extensive subsurface cavities in the solar system,” they wrote in the paper.
The findings could allow us to better understand Venus’ “thermal and tectonic evolution, and offer exciting possibilities for understanding the planet’s past and present conditions,” they concluded.
The team is calling for the European Space Agency’s upcoming EnVision mission‘s Subsurface Radar Sounder (SRS) instrument to have a closer look. The probe is set to launch to Venus in late 2031, in an effort to understand why Earth’s closest neighbor is “so different,” according to the agency.
More on Venus: NASA Installs Heat Shield on Private Spacecraft for Journey to Hunt Life on Venus