Written by PPL Newsroom• October 4, 2026• 5:26 am• Climate & Environment

Satellite studies show India’s night is getting brighter, and the stars are fading

Research tracks rising outdoor lighting across states and river basins, while Hanle in Ladakh shows how a community can keep its sky dark.

Across India, outdoor lighting is growing brighter and spilling further into the sky, and the stars are the first casualty. Satellite-based studies show night-time brightness rising in many states and along major rivers. This affects astronomers, wildlife and anyone who would like to see the Milky Way from home.

What the measurements show

A study in the journal Urban Climate, published in January 2019, used satellite imagery to track outdoor brightness over two decades. New Delhi, Telangana, Maharashtra, Karnataka and Uttar Pradesh saw “very high light pollution intensity” increase between 1993 and 2013. West Bengal, Gujarat and Tamil Nadu moved from low to high light pollution. Study author Pavan Kumar of Jamia Millia Islamia said only Assam and Madhya Pradesh showed a decrease over that period.

A 2017 global study, cited in coverage of the work, found that India’s “loss of night” from artificial light was three times faster than the global average.

The glow reaches beyond cities. A later study of Indian river basins found average night-time radiance rose 1.8-fold between 2012 and 2020. Its authors flagged concern for the critically endangered gharial, which mostly lives in darker habitats. They also noted that brightness was high in biodiversity-rich stretches, including the Ganga and Chambal.

Why the sky is losing its stars

Skyglow forms when light from towns and cities is directed upward and scatters in the air, creating a visible glow. Researchers also point to LEDs used without proper shielding or protection against over-illumination.

Planners say the cause is the physical growth of cities rather than economic output. Researcher Bedi told IndiaSpend that brightness rises with real estate, highways and urban sprawl, not GDP volume as such. Her team at the School of Planning and Architecture, Bhopal, named Bengaluru, Kolkata, Hyderabad, Delhi and Mumbai as India’s most light-polluted cities. They also found streets lit to four times the level the Indian Standards recommend.

What is working: Hanle

One place is trying to hold the line. In December 2022, Hanle in Ladakh was declared India’s first dark sky reserve. It covers 1,073 square kilometres around the Indian Astronomical Observatory. Twenty-four local astronomy ambassadors were trained, the Indian Institute of Astrophysics gave homestays warm-coloured bulbs and lampshades, and a Light Management Plan set the rules.

The challenge is not over. A recent India Forum analysis says light pollution at Hanle is increasing and India has no national law to address it.

What this means for India

Responsibility for public lighting sits with local bodies. Bedi told IndiaSpend that municipal corporations, development authorities and gram panchayats run it, but compliance with Indian Standards is hindered by low awareness and a lack of specific regulations. With no national law, the practical lessons come from cities and communities. Streets lit well above the recommended level are a clear target for correction. Hanle shows that shielded, warm-toned lighting agreed with residents can protect a dark sky.

Nobody is arguing for dark streets. The research points to better-aimed, better-shielded lighting, so that light falls where people need it and not into the sky.