Underneath the surface of the Moon and Mars, there are vast caverns known as lava tubes that were created by volcanic activity. Now, researchers have claimed we could live in them.
Presented at the European Planetary Science Congress in Riga, Latvia, researchers from the University of Padova and the University of Bologna in Italy suggested it was possible to place habitats in these lava tubes.
On Earth, our paltry tubes reach only about 30 meters (100 feet) across. On Mars however, they can be up to 250 meters (820 feet) in width, while on the Moon they can be 1 kilometer across and hundreds of kilometers in length.
Being underground, these caverns are shielded from cosmic radiation. Thus, the researchers say they are not only possible habitats for humans, but they may also play host to life elsewhere.
“Lava tubes are environments shielded from cosmic radiation and protected from micrometeorites flux, potentially providing safe habitats for future human missions,” said Dr Riccardo Pozzobon, of the University of Padova in a statement.
“They are also, potentially, large enough for quite significant human settlements – you could fit most of the historic city center of Riga into a lunar lava tube.”

In fact, European astronauts have already been training in Earth lava tubes, as part of a course called PANGAEA. This planetary geology course is intended to prepare astronauts for new environments. A recent field trip took place in lava tubes in the Canary Islands to familiarize astronauts with the geological research they could conduct on missions to the Moon or Mars.
We have considered lava tubes as potential habitats for humans before, but this is the first study to look at the key differences between tubes on Earth and the Moon and Mars, using high-resolution Digital Terrain Models (DTM). The lack of weathering and erosion on the Moon has enabled these tubes to become enormous, big enough to house a city.
At times it’s hard to fathom just how big these lava tubes are. They can stretch for up to 65 kilometers (40 miles) in length, in addition to their rather impressive width. They can form in one of two ways, either when low-viscosity lava flowed to the surface and hardened, or when lava expanded underground and left huge networks of tunnels behind.
We can see some openings to some of the pits on the Moon today, with more than 200 holes possibly leading to underground tunnels. We’re yet to properly explore one yet, but perhaps astronauts in the future will venture down into these sheltered zones.