Sci-fi fans would be undoubtedly unnerved by the idea of giant tunnels under the surface of planets.

So it’s no wonder that the discovery of massive underground tunnels on Venus have been big news recently.

The good news? They don’t house an ominous threat of the monster variety.

In fact, the subterranean tunnels are the result of the behavior of ancient molten rock – and most surprisingly, these long-present lava tunnels are also present much closer to home.

Lava tunnels are long-established parts of the geology of Mars, the Moon, and even our home planet, Earth.

But this is the first time that such tunnels have been detected on Venus, as explained in a recent paper by the University of Padova’s Barbara De Toffoli.

However, there’s something quite surprising about Venus’s newly-discovered lava tubes. As De Toffoli explained in New Scientist, the tunnels are much bigger than their Earth-like gravity should allow:

“Earth lava tubes have smaller volumes, Mars tubes have slightly bigger volumes, and then the Moon’s tubes have even bigger volumes. 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.”

So why haven’t these massive tunnels collapsed under the pressure of Venus’s gravity, which is similar to that on Earth?

Well, as De Toffoli and her team hypothesise, this could be a result of the immense heat and pressure found on the planet, with the volume of the tunnels really marking out this hot, rocky planet as different to others in our solar system in more ways than previously known:

“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, [with] exciting possibilities for understanding the planet’s past and present conditions.”

With this in mind, the team are keen to press on, delving deeper to understand more about this curious planet than ever before.

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