Hanle in Ladakh has been identified as one of the potential alternate sites for the Thirty Meter Telescope (TMT). The original site for TMT was Mauna Kea in Hawaii in the United States of America. 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.

Shri Y.S. Chowdary, Minister of State for Science & Technology and Earth Sciences, in a written reply to a Question in Rajya Sabha today, informed the House that in view of significant investments and efforts already made towards realizing the project, it has been decided by the TMT Partner Countries to look for alternate sites, including Hanle, as fall-back options.

Further, the Minister, through the reply, informed that India’s participation in the TMT project is being jointly funded and overseen by the Department of Science and Technology (DST) and the Department of Atomic Energy (DAE), with DST as the Lead Agency. DST has received clearances from the Ministry of Defence, Ministry of Home Affairs and Ministry of External Affairs for hosting TMT at Hanle in Ladakh.

The Minister also informed that Indian scientists leading this project, led by the Indian Institute of Astrophysics, Bengaluru, visited the region and have completed measurements of the key scientific parameter, viz. ‘Atmospheric turbulence or Seeing measured in arc-second’.

The necessary site-specific details have been submitted to the TMT alternate site selection team. Hanle site has lower seeing values of 0.9-1.2 arc sec as compared to the alternate sites in Chile and Canary Islands of Spain (La Palma) which have seeing values of 0.55 arc sec. Thus, scientifically, Hanle has less advantageous characteristics for hosting a mega telescope like the TMT in comparison to the other alternate sites, the reply added.