The Department of Science and Technology (DST) and experts from the Indian Institute of Astrophysics (IIA) have undertaken a first-of-its kind project to set up a dark sky reserve (DSR) in Changthang Wildlife Sanctuary, Hanle, in Ladakh, by the beginning of 2023. In June 2022, a three-way memorandum of understanding (MoU) was signed among the Union Territory administration, Ladakh Autonomous Hill Development Council (LAHDC), Leh, and the IIA (Bengaluru). IIA already maintains the Indian Astronomical Observatory (IAO) in Ladakh for this purpose. The facility would also have activities aimed at boosting local tourism and further the economy.
India is still in the process of filing its nomination to the International Dark Sky Association (IDSA).
What is Dark Sky Reserve?
A dark sky reserve is the name given to a place, either private or public, which has policies in place to ensure that land has minimal light pollution. This place has an exceptional or distinguished quality of starry nights and a nocturnal environment. It is protected for its scientific, natural, or educational value, its cultural heritage, and public enjoyment.
According to the IDSA, a DSR consists of a core area meeting minimum criteria for sky quality and natural darkness, and a peripheral area that supports dark sky preservation in the core. Further, these reserves are formed through a partnership of multiple land managers who have recognised the value of the natural night-time environment through regulations and long-term planning.
Categories and Recognition
Individuals or groups could nominate a site for certification to the IDSA. Between 2001 and January 2022, 195 sites have been recognised as international dark sky places, globally.
There are five designated categories, namely, International Dark Sky Parks; International Dark Sky Communities; International Dark Sky Reserves; International Dark Sky Sanctuaries; and Urban Night Sky Places.
The parks are public or private places protected for natural conservation to implement good outdoor lighting and to provide dark sky programmes for visitors. Communities are legally recognised cities and towns that adopt quality outdoor lighting ordinances and attempt to educate residents about the importance of dark skies. A dark ‘core’ zone surrounded by a populated periphery where policy controls are enacted in order to protect the darkness is known as dark sky reserve. As for dark sky sanctuaries, they refer to the most remote zone in the world in most fragile conservation state. And lastly, urban night sky places refer to sites near or surrounded by large urban environs. Their planning and design promote an authentic nighttime experience in the midst of artificial night light.
A piece of land is recognised as a dark sky place only if it is either publicly or privately owned and is accessible to the public partially or entirely during the year; it should be legally protected for scientific, natural, educational, cultural, heritage and/or public enjoyment purposes. Besides, the core area of the land should provide an exceptional dark sky resource relative to the communities and cities around it. The piece of land must also offer prescribed night sky brightness either for a reserve, park, or sanctuary.
Choice of Ladakh for Dark Sky Reserve
Ladakh has been chosen to be set up as a DSR because it is a cold desert located about 3,000 metres above the sea level with high mountainous terrains. With a minimum temperature of minus forty degrees Celsius, Ladakh’s long and harsh winters make its large parts inhabitable. Other reasons include the aridity, limited vegetation, high elevation, and large areas with sparse populations.
The Indian Astronomical Observatory (IAO), is situated to the north of Western Himalayas, at an altitude of 4,500 metres above mean sea level. The Hanle Valley of Changthang is located above Mount Saraswati, in the Nilamkhul Plains, and is a dry cold desert with sparse human population. The Hanle Monastery is in its vicinity. These conditions make Hanle one of the best sites in the world for optical, infrared, and sub-millimetre and millimetre wavelengths. So, scientists carry out astronomical observations here using the existing gamma ray, an infrared, and an optical telescope.
The Himalayan Chandra Telescope (HCT), the High Altitude Gamma Ray Telescope (HAGAR), the Major Atmospheric Cherenkov Experiment Telescope (MACE), and the Global Relay of Observatories Watching Transients Happen (GROWTH), are prominent telescopes located at the Hanle observatory.
The primary objective of the proposed DSR is to promote astronomy tourism in a sustainable and environment-friendly manner. Scientific methods would be used to preserve the night sky from night pollution. The Tourism Vision Document for Ladakh 2022 has underlined the need for efforts to increase the use of green fuels to boost carbon-neutral activities. According to the Director of IIA, Annapurni Subramaniam, the locals of Ladakh are sensitive towards the conservation of the ecosystem. That’s why experts of IIA have held active interactions with the locals and have taken many initiatives. For example, they have given hand-outs to villagers, sharing details about the training programmes. In the pilot phase, the IIA has procured 10 small and easy-to-handle telescopes, and light-reflecting shields. IIA experts would also identify locals, and train them in using the telescopes for basic sky gazing, identification of constellations and locating the pole star, among others. These telescopes would be installed at the homestays, where tourists could have their accommodation.
The 22-km radius around the Hanle observatory, the core area of the DSR, would have restrictions imposed on outdoor lighting—all vehicles would be barred from using high-beam headlights and houses would be encouraged to use curtains of darker shades, install light reflecting shields and switch off all unwanted illumination.
At present, there are 20 DSRs around the world—eight in the UK: Cranborne Chase (2019), Exmoor National Park (2011), Moore’s Reserve (2016), North York Moors National Park (2020), Yorkshire Dales National Park (2020), Brecon Beacons National Park (2013), Snowdonia National Park (2015), and Kerry (2014); four in France: Alpes Azur Mercantour (2019), Cévennes National Park (2018), Pic du Midi (2013), Regional Natural Park of Millevaches in Limousin (2021); two in the USA: Central Idaho (2017), Greater Big Bend International Dark Sky Reserve (2022); two in Germany: Rhön (2014), Westhavelland (2014); one in New Zealand: Aoraki Mackenzie (2012); one in Canada: Mont-Mégantic (2007); one in Namibia: NamibRand Nature Reserve (2010); and one in Australia: River Murray (2019).
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