The discovery was made by┬áJapan’s orbiting Selenological and Engineering Explorer (Selene) probe, using a special radar system which is capable of examining underground structures. The huge cave is believed to be stable and stretches for an impressive 50km, also boasting a width and depth of about 50 metres.

It is thought to be a lava tube formed by volcanic activity on the moon approximately 3.5 billion years ago, and scientists believe it is possible it could contain ice on the walls, making it an ideal location for astronauts to setup base.

“We’ve known about these locations that were thought to be lava tubes… but their existence has not been confirmed until now,” said JAXA senior researcher Junichi Haruyama.

“[Lava tubes] might be the best candidate sites for future lunar bases, because of their stable thermal conditions and potential to protect people and instruments from micrometeorites and radiation.”

JAXA is hopeful of launching a manned mission to the moon by 2030, which by then researchers will hopefully have gathered much more information about the structure.

“We haven’t actually seen the inside of the cave itself so there are high hopes that exploring it will offer more details,” said Haruyama.