Space scientists have discovered an odd hole in the Moon. They believe the deep pit – the first ever found – leads to a huge underground tunnel, called a lava tube.

The hole, which is about 70 yards wide, lies in a volcanic area on the Moon’s near side called Marius Hills.

It was spotted as a dark dot as researchers scoured photos taken by Japan’s Kaguya probe before it ended its mission by crashing in June.

The hole appears to be at least 90 yards deep and the rock pattern suggests that it is connected to a tunnel 400 yards wide.

Astronomers believe underground tunnels may be common the on Moon, caused by molten lava that flowed billions of years ago.

But this is the first found with an entrance. Experts say it could be adapted to shelter future lunar colonists from deadly radiation from the Sun and space. The discovery came as Japanese and German scientists searched for signs of “skylights” or entrances to the underground tunnels.

“This is the first time that anybody’s actually identified a skylight in a possible lava tube” on the Moon, Carolyn van der Bogert of the University of Münster, in Germany, told New Scientist online.

Scientists are now waiting for NASA’s latest Moon probe, Lunar Reconnaissance Orbiter, to take detailed close-up pictures of the hole to tell them more about it.

Picture: A photo from Kaguya showing the strange hole. (Credit: ISAS, JAXA, Junichi Haruyama et al.)

• Discover space for yourself and do fun science with a telescope. Here is Skymania’s advice on how to choose a telescope. We also have a guide to the different types of telescope available.