For three decades, a giant tunnel has been hiding in plain sight — buried beneath the surface of Venus, and lurking unnoticed in data collected by a NASA spacecraft that last operated in 1994.
Now, a team of scientists from the **University of Trento in Italy** has found it. Published in *Nature Communications* in February 2026, their study presents the strongest evidence ever found for a **massive lava tube on Venus** — a planetary cave so large that it dwarfs anything found on Earth, and makes even the most ambitious lava tube estimates for Mars look modest.
**What They Found — and How**
The researchers returned to archival radar data from NASA's **Magellan spacecraft**, which mapped 98% of Venus's surface between 1989 and 1994 before its mission ended. Using new analytical techniques, they re-examined a feature near the **Nyx Mons shield volcano** and identified something remarkable: a "skylight" — a collapsed section of a lava tube's roof.
The structure they identified is estimated to be: - 📏 **Nearly 1 kilometre in diameter** - 📏 **300 metres tall** inside - 🪨 **At least 150 metres of roof** still intact above it - 📍 Potentially **dozens of kilometres long** extending underground
For comparison: the largest confirmed lava tube on Earth is roughly 30 metres wide. The Martian tubes predicted by some researchers top out at around 400 metres. The Venusian tube described in this paper is in a different category entirely.
**Why Lava Tubes Form — and Why They Matter**
Lava tubes are natural conduits formed when molten rock flows beneath a hardened crust. On Earth, they honeycomb volcanic regions like Hawaii and the Canary Islands, and on the Moon and Mars, they represent some of the most intriguing potential sites for future exploration — offering natural shelter from radiation, temperature swings, and micrometeorite impacts.
On Venus, the finding transforms our understanding of the planet's geological history. Venus is covered in volcanoes and is now believed to be volcanically active — but the internal structure of its crust has remained mysterious. The existence of a lava tube of this scale suggests **far more complex subsurface geology** than previously confirmed, and hints at a volcanic past that was exceptionally dynamic.
**A Door Opened for Future Missions**
The discovery arrives at a pivotal moment. Two major Venus missions are in development: - 🛸 **ESA's EnVision** — equipped with advanced radar capable of far higher resolution than Magellan - 🛸 **NASA's VERITAS** — designed specifically for subsurface imaging and surface geology
Either mission could, in theory, directly probe the Nyx Mons tube and the surrounding network. If lava tubes on Venus prove widespread — as this evidence suggests they might — they would become primary scientific targets, offering windows into the planet's interior and its volcanic timeline.
**Thirty Years of Hidden Treasure**
Perhaps the most striking element of this discovery is where it came from: data collected by a spacecraft that finished operating before the World Wide Web went public, waiting three decades for someone to look at it with fresh eyes and better tools.
It's a reminder that even in an era of new missions and cutting-edge observatories, the archives hold surprises. Magellan is gone. But its legacy just got a lot more interesting. 🪐
*Sources: University of Trento / Nature Communications, February 2026 / NASA Magellan Archive / European Space Agency*