Hanle is one of the best sites in the country to build observatories due to its dark skies, dry weather, and cloudless nights. Since dark skies are threatened by light pollution caused by unwanted illumination, it is crucial to preserve the darkness of the skies in Hanle as the local neighbourhood develops socio-economically. Reducing light pollution benefits the local environment as well. By appropriately shielding all outdoor lights, a large part of the illumination will fall downwards where it is needed, instead of upwards or sideways. Shielded lights require less wattage and saves energy. The glare due to lights shining directly into our eyes blinds us to darker objects, and is hence unsafe.
The Changthang Wildlife Sanctuary is home to unique wildlife, including nocturnal animals, and bright lights at night time will interfere with them. But the most important reason is that dark skies, where we get to see the stars in all their beauty, are a part of our natural and cultural heritage. With such places dwindling around the world, some countries have created dark sky sanctuaries that attract people who want to experience its enchantment. Many of these sanctuaries are centred around major astronomical observatories.
Hence a Dark Sky Reserve was proposed centered around the Indian Astronomical Observatory where certain regulation will be applicable to all outdoor lighting, sheilding and use of high beams while driving. Such a reserve will protect the skies above the observatory and the site will continue to be the best astronomical location in the country. The project have a crucial component of astro-tourism, whereby the dark skies are used for income generation for the communities in the Sanctruary.
