In a landmark discovery, India's maiden moon mission Chandrayaan-I has found evidence of water on the lunar surface, a finding that could trigger a serious hunt for life in outer space.

In a major leap for India’s space programme, the Moon mapper on-board the Indian space probe made the unexpected discovery that water may still be forming on the moon surface overturning the long accepted view that lunar soil is dry.

There are strong chemical signatures of water on the moon in its high latitudes, said Carle Pieters, principal investigator of Nasa’s Moon Mineralogy Mapper (M3) instrument. Chandrayaan-I, whose mission also included sniffing for water on earth's only natural satellite, had made the discovery before it was prematurely aborted on August 30.

Meanwhile, amid euphoria over the Chandrayaan-I finding, some scientists had a word of caution on the discovery saying there was a need to quantify the reserves.

"The results suggest that frost rather than water is present in the form of a thin film on the lunar surface. The quantity and its distribution across the moon is still an open question," K Kasturirangan, former Isro chairman said.

Kasturirangan, who conceived the Chandrayaan-I mission, said the findings by a team of Nasa ccientists was very significant as it had been eluding researchers for a long time.

"Ultimately, in the long run if humankind has to go and inhabit the moon, one of the important requirements is that you should have adequate water for survival," he added.

Isro scientists J N Goswami and Mylswamy Annadurai, who made key contributions to the study, however, were ecstatic about the findings, which could unleash another round of moon missions. "Our baby has done its job," Annadurai, project director for Chandrayaan-I, said on phone from Bangalore.

Pieters published her findings in the latest issue of Science magazine where she said that M3 results show presence of small amounts of water on the uppermost surface of the moon. While the mangintude was not precisely known, scientists believe that a tonne of lunar soil could fetch about a litre of water.

"If it weren't for them, we wouldn't have been able to make this discovery," Pieters said crediting Isro for its role in the findings.

Isro chairman G Madhavan Nair said in Bangalore the discovery was "path-breaking" saying no lunar odyssey so far had given a "positive" conclusion.

"There is confirmation of traces of water. It is a path-breaking event as far as Chandrayaan-1 mission is concerned. It is very very significant. So far, no mission has confirmed the presence of water positively," Nair said.

Until now, scientists had advanced the theory that there might be ice at the permamently dark bottom of craters at the Moon's poles but that the rest of the moon was totally dry. Now, the finding ends four-decade long speculation on whether there is water on moon.

Scientists first claimed that water existed on moon about 40 years ago after they analysed rock samples brought to earth as souvenirs by Apollo astronauts.

But they had doubts about the findings as the boxes in which the moon rocks were brought to earth had leaked contaminating the samples with air from the atmosphere.