NEW DELHI: India has lost out on being the destination for the world's largest telescope There was a lot of anticipation that the giant Thirty Meter Telescope (TMT) would get housed at a remote high- altitude site in the cold desert of Ladakh in Jammu and Kashmir.This week members of the multi-country coalition that is spearheading it decided to build the telescope in the Canary Islands in the Atlantic Ocean. A telescope that would cost upwards of USD 2 billion by the time it is becomes operational in 2025.Many say this was a much favoured project of Prime Minister Narendra Modi since within four months of taking over, the TMT project found favour with the National Democratic Alliance and was one of the first mega science projects cleared by Modi's cabinet.Studying the origins of the universe and deciphering what is dark energy would be the key objectives of this mega global exercise.According to a report by the Indian government, "The TMT will enable scientists to study fainter objects far away from Earth in the Universe, which gives information about early stages of evolution of the Universe."Also, it will give scientists finer details of not-so-far- away objects like undiscovered planets and other objects in the solar system and planets around other stars.TMT being the largest optical and infrared telescope in the northern hemisphere would enable several discoveries. Competing with the TMT is the 39-m-diameter European Extremely Large Telescope that is likely to come up in Chile, which if all goes well should see first light in 2024.The preferred site to house the giant TMT was on a 4050-m- high mountain in Hawaii called Mauna Kea but the local courts in Hawaii heard protest petitions from the local people who felt the making of the telescope violated a 'sacred site' and in 2015 much against the wishes of the global scientific community construction was halted at Hawaii on orders of the court. This led to a lot of uncertainty.Since then a search was made for the best alternative sites and Hanle in India at 4500 metres in the cold dry environs of the Himalayas was very actively considered. At Hanle, India already houses the world's highest optical telescope run by the Indian Institute of Astrophysics (IIAP), Bengaluru Professor Eswar Reddy, lead scientist on the project from the IIAP, says, "Hanle remains a very good site but the turbulence of air over it was rather high to house a giant telescope."Also adding that the nearest port was too far at Mumbai and road access to Hanle gets blocked for several months due to heavy snow and some of these factors went against the Indian site, despite the fact that the Indian government had laid a red carpet for the TMT project to be housed in India.On September 24, 2014 the Union Cabinet chaired by Modi, gave its approval for India's participation in the TMT Project at Mauna Kea, Hawaii, US at a total cost of Rs 1299.8 crore from 2014-23.The government brief said the TMT will be constructed at a cost of USD 1.47 billion by an international consortium consisting of institutions from the US, Canada, Japan, India and China . From the Indian side, this will be a joint project of the Department of Science and Technology (DST) and the Department of Atomic Energy (DAE). With its contributions, India will be a 10 per cent partner in the project and 70 per cent of its contributions will be "in kind".This will translate into 25 to 30 observing nights on the telescope for Indian scientists per year. This will enable Indian scientists to access a state-of-the-art telescope to answer some of the most fundamental questions in modern science.Indian institutions and industry will acquire or gain access to sophisticated technologies of relevance to the country. India will also become a founding member of an important international scientific project.The promoters of TMT said it will enable scientists to study fainter objects far away from us in the Universe, which gives information about early stages of the evolution of the Universe.It will also give finer details of not-so-far-away objects such as undiscovered planets and other objects in the solar system and planets around other stars. This partnership will also enhance India's technological capabilities in high- technology areas such as primary mirror segment figuring and polishing, mirror support system and edge sensor assembly and testing, software for observatory controls, data analysis pipelines, adaptive optics techniques etc.The IIAP notes that the TMT will be one of the largest optical-infrared telescopes to come up in the next decade. Its 30 metre diameter primary mirror will consist of 492 segments of 1.44-m-diameter each. These mirror segments will be cleverly positioned relative to each other through sophisticated sensors, actuators and control systems, so that the entire assembly behaves like single monolithic mirror.Its performance will be further improved by employing "adaptive optics" techniques thereby achieving performance as if the telescope is located above the Earth's atmosphere.Hopes were high and less than three months ago India's science minister informed the Parliament "Hanle in Ladakh has been identified as one of the potential alternate sites for the TMT. The original site for TMT was Mauna Kea in Hawaii. The construction work for TMT at Mauna Kea was started but had to be stalled due to revocation of Permit by orders of the Supreme Court of Hawaii and Hanle, was a fall-back option."Hanle being close to the Chinese border, the minister said the Department of Science and Technology (DST) had received clearances from the Ministry of Defence, Ministry of Home Affairs and Ministry of External Affairs for hosting it in Ladakh.The Minister did add a dampener by saying that the scientists who visited the region and completed measurements of the key scientific parameter, namely 'Atmospheric turbulence or Seeing measured in arc-second'. Hanle site had a lower seeing values of 0.9-1.2 arc second as compared to the alternate sites in Chile and Canary Islands of Spain (La Palma) which have seeing values of 0.55 arc seconds.The science minister said, "Scientifically, Hanle has less advantageous characteristics for hosting a mega telescope like the TMT in comparison to the other alternate sites."In the end, Reddy says it was scientific reasons that made TMT governing board decide to try and shift the project to Canary Islands if Hawaii remains out of bounds.