What’s in the news?

• The Government of India recently announced that by the end of 2022, India will establish the country’s first Dark Sky Reserve at Hanle.
• The Hanle Dark Sky Reserve (HDSR) will come up within the Changthang Wildlife Sanctuary and the facility will also promote astronomy-tourism.
• The Ladakh Union Territory administration is leading the efforts in establishing the Dark Sky Reserve. The Department of Science and Technology and experts from the Indian Institute of Astrophysics (IIA) are providing scientific and technological support in developing this first-of-its-kind facility.
• The IIA already manages the Indian Astronomical Observatory (IAO) complex at Hanle, Ladakh.

What is a Dark Sky Reserve? 

• A Dark Sky Reserve is public or private land with a distinguished nocturnal environment and starry nights that has been developed responsibly to prevent light pollution.
• These reserves consist 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.

How does a site become a ‘Dark Sky Reserve’?

• Individuals or groups can nominate a site for certification to the International Dark Sky Association (IDSA). There are five designated categories, namely International Dark Sky parks, communities, reserves, sanctuaries and Urban Night Sky Places.
• The certification process is similar to that of a site being awarded the UNESCO World Heritage Site tag or getting recognised as a Biosphere Reserve. Between 2001 and January 2022, there have been 195 sites recognised as International Dark Sky Places globally.
• The IDSA considers a piece of land suitable for dark sky place only if:
  • it is either publicly or privately owned;
  • is accessible to the public partially or entirely during the year;
  • the land is legally protected for scientific, natural, educational, cultural, heritage and/or public enjoyment purposes;
  • the core area of the land provides an exceptional dark sky resource relative to the communities and cities that surround it and
  • the land offers prescribed night sky brightness either for a reserve, park or sanctuary.
• India is still in the process of filing its nomination to IDSA.

Related Information

Hanle Space Observatory 

• The Indian Astronomical Observatory (IAO) located at Hanle near Leh in Ladakh is becoming one of the most promising observatory sites globally. This is due to its advantages of more clear nights, minimal light pollution, background aerosol concentration, extremely dry atmospheric conditions, uninterrupted by rains.

• To be able to detect stars or traces of cosmic phenomena, such as supernovae or nebulae from light years away, astronomers must be able to catch the faintest slivers of their radiation that often lie outside the range of visible light. 
• Such radiation is, however, easily absorbed by water vapour and so it helps to have a telescope high above ground where the atmosphere is drier. 

About the Observatory

• Situated at 14,000 ft above sea level, IAO is laid out on the mountain called Digpa-Ratsa Ri, aka Mt Saraswati.
• IAO houses the Major Atmospheric Cherenkov Experiment Telescope (MACE) built by a consortium of the Bhabha Atomic Research Centre, the Tata Institute of Fundamental Research, the Electronics Corporation of India Ltd. and the Indian Institute of Astrophysics (IIA).
• Its goal is to detect Cherenkov radiation from space. This is a special kind of light from gamma rays, or the most energetic sources of radiation, that can result from dying stars or several galactic events. 
• IAO consists of a seven-telescope contingent, called HAGAR (High Altitude Gamma Ray), which also looks at Cherenkov radiation, although at a lower range of energies.
• An optical-infrared telescope with a 2-metre lens is designed to detect light from the visible range of the electromagnetic spectrum as well as that just below it, or the infra-red spectrum. 
• The second capsule is the GROWTH-India telescope, a 70-cm telescope that is equipped to track cosmic events that unfurl over time, such as afterglows of a gamma ray burst or tracking the path of asteroids. 
• Because of the wide span of frequencies covered collectively, the IAO provides multiple vantage points to observe a range of cosmic phenomena and investigate the mysteries of the universe.
• Telescopes with small diameters generally can track a greater swath of sky but those with larger diameters can peer deeper when trained towards desired locations.

Reference:

1. https://www.thehindu.com/sci-tech/science/indian-astronomical-observatory-in-hanle-ladakh-where-the-stars-must-not-twinkle/article65980330.ece