Ahmedabad: After the successful discovery of water on moon, the Indian spacecraft Chandrayaan - 1 has made another startling discovery and has found large caves on the lunar surface. Scientist believe that these can act as human shelter on moon.

"We have discovered a natural tunnel near the equator of the Moon which is even bigger than that discovered by the Japanese. This is a empty volcanic tube, measuring about two kilometer in length and 360 meters in width. This could be a potential site for human settlement on moon," said AS Arya, scientist SF of Ahmedabad-based Space Application Centre (SAC). Arya told Economic Times on the sidelines of a two-day conference at Physical Research Laboratory (PRL) on Monday. Arya will also be presenting a paper on the discovery at the LPC (Lunar and Planetary Science Conference) scheduled to be held at Houston from March 1-5.

Earlier, Japanese aircraft Kaguya had also discovered a cave on moon. This spacecraft had discovered a tunnel which was 65 m wide and 80 m deep in the volcanic Marius hill range on the lunar surface "This is a horizontal cave and is much bigger than the Japanese discovery. This finding would go a long way in India's quest to set up a permanent base on the Moon. Such wide tunnels could sustain underground lunar outposts, while the ceilings could help protect astronauts from space radiation, meteoroid impacts and wild temperature fluctuations (up 300 degree centrigrade) that is commonplace on the lunar surface," Arya explained.

Scientists have long suspected that such rock formations existed on the moon, but lacked evidence until now. According to scientists, Lunar lava tubes are a potentially important location for a future lunar base, whether for local exploration and development, or as an outpost to serve exploration beyond the moon.

"The findings happened while the data from the TMC (Terrain Mapping Camera) was being analysed. Moreover, this particular cave is situated near the equator where most of the lunar missions have landed so far," Arya said. The TMC was one of the five Indian payload that was onboard Chandrayaan-I.