There’s an air of expectancy over the Spirit rover’s exploits on Mars, but not many know that this place on earth is one of the main reasons why it is so. Coinciding with the Mars exploration, a geophysicist associated with the National Aeronautics and Space Administration (NASA) is studying the surface of one of only two impact craters created by a meteor strike on basaltic land, which is located at Lonar in Maharashtra. Horton Newsom, a research professor, is here to collect samples on NASA’s request in a bid to unlock the mysteries of the Martian surface. The reason is the uncanny similarities between the Lonar crater and those on Mars, which are also formed in basalt. By comparing samples from Lonar with those from Mars, scientists hope to solve the one big riddle surrounding the red planet: Did it ever contain water? Could it ever support life? The Spirit rover has already wandered over the surface of one such Martian crater, though a much bigger one. Newsom, from the Institute of Meteoritics at New Mexico University in US, was among those responsible for selecting the site. ‘‘Lonar comes closest to Martian craters in terms of chemistry,’’ Newsom told The Indian Express. ‘‘Since not much is known about the only other basaltic crater, which is in Russia, Lonar offers great prospectsfor better understanding of Mars.’’ Newsom, in fact, is part of a four-member Lonar exploration team along with co-scientists Soumitra Misra, D. Sengupta and V.L. Narasimhan from IIT, Kharagpur. The team’s study is aimed at identifying major alterations at the site (conversion of rock to soil) and to check if this was due to impact-induced hydrothermal activity (which takes place after groundwater seeps through fractures caused by the collision of a meteor with the host rock). In a paper published in a journal called Meteoritics and Planetary Science last year, Newsom had said that the 50,000-year old, 1.8-km diametre crater at Lonar offers an excellent analog for similarly-sized craters on Mars as it has a composition similar to that of Martian meteorites. ‘‘Hydrothermal alterations at Lonar suggest Lonar-sized Martian craters may also have potential to form hydrothermal systems leading to such alterations if water is present there in some form,’’ he said. ‘‘With impact craters’ known ability to access shallow groundwater, this could have become possible on Mars as well.’’ Newsom has also done some geo-chemical modelling of Martian basalt alterations to strengthen the analogy. ‘‘Our results suggest Lonar has great potential as a laboratory for Martian study, and needs to be urgently protected,’’ he said. The warning could not have been better timed. Use of chemical fertilisers and pesticides by farmers doing agriculture right inside the crater poses a serious ecological danger to the site. ‘‘Many such warnings have been issued so far,’’ says S.T. Bugdane, a local teacher and an amateur geology enthusiast. Thick plantations on the slopes of the crater are dwindling, with the result that rains cause the soil to slide down and get accumulated at the base, he said. ‘‘Some of the 18 beautiful temples at the crater’s base have disappeared as water levels rise.’’ But the authorities are, at long last, waking up. Says District Collector Dinesh Waghmare: ‘‘The Forest Department has declared it a wildlife sanctuary. We gave them Rs 45 lakh last year for purposes like chain-fencing and a nature-interpretation centre, but they returned it.’’ Deputy Conservator of Forest Shailesh Tembhurnikar says the measures could not be implemented as some environmentalists had reservations. Now there are plans to declare Lonar a World Heritage site. Given its links to the only other planet with possibility of human habitation, about time too..
