A deep pit on the Moon might lead to a cave that could potentially serve as a lunar base.

We may have identified a potential entry point to caves beneath the Moon’s surface, which could offer protection from harmful radiation for future astronauts.

There is probably a network of caves hidden just below the surface of the moon, and researchers may have finally found an access point. These caves have long been predicted, but until now it has been difficult to prove their existence or find a way for future missions to explore them directly.

The surface of the moon is riddled with pits and so-called skylights, which are openings in the roof of a cave that are thought to have formed from the collapse of ancient lava tubes – tunnels formed as lava flows beneath a solid crust. Leonardo Carrer at the University of Trento in Italy and his colleagues re-analysed radar observations of the deepest known of these features, called the Mare Tranquillitatis pit, which were taken by NASA’s Lunar Reconnaissance Orbiter in 2010.

Using simulations and comparisons to lava tubes on Earth, the researchers found that the Mare Tranquillitatis pit seems to lead to a large cave buried at least 130 metres underground. The cave seems to be about 45 metres wide and at least 30 metres long, although it could be even larger.