Scientists at Japan's space agency have discovered a huge moon cave that could one day house a base that would shelter astronauts from dangerous radiation and wild temperature swings, officials said on Thursday.

Data taken from Japan's SELENE lunar orbiter has confirmed the existence of the 31-mile-long and 328-foot-wide wide cavern that is believed to be lava tube created by volcanic activity about 3.5 billion years ago.

The major finding was published this week in U.S. science magazine Geophysical Research Letters.

"We've known about these locations that were thought to be lava tubes ... but their existence has not been confirmed until now," Junichi Haruyama, a researcher at the Japan Aerospace Exploration Agency, told AFP on Thursday.

The underground tunnel, located under an area called the Marius Hills, would help protect astronauts from huge swings in temperature and damaging radiation that they would be exposed to on the moon's surface, he added.

"We haven't actually seen the inside of the cave itself so there are high hopes that exploring it will offer more details," Haruyama said... More ... (AFP)