In an exceptional display of scientific curiosity, 17-year-old Suhani Gupta from Gurugram has created SkyQI, a free online platform that uses smartphone photographs to measure night sky brightness, addressing the issue of light pollution. This innovative project was born out of Suhani's concern about the diminishing visibility of stars due to urban lights in her city.
Suhani, a Class 12 student, noticed a significant difference in star visibility during her visits to her grandparents in Udhampur, Jammu and Kashmir, where skies were much darker compared to cities. This observation led her to explore the idea of light pollution, a lesser-known form of environmental pollution that occurs as cities expand and outdoor lighting becomes more widespread.
The initial version of SkyQI assessed the overall brightness of photographs but was found to be unreliable due to factors like clouds. Suhani then redesigned the platform to examine three indicators: the number of visible stars, the difference in brightness between the horizon and the sky directly overhead, and the calculated brightness of the sky. The website went live in 2025, with safeguards to account for variables such as cloud cover, camera settings, and image quality.
In 2026, Suhani analyzed a decade of NASA satellite observations covering 50 Indian cities, comparing night-time radiance in 2015, 2020, and 2025. Her findings revealed that median night-time radiance across the 50 cities was 70% higher in 2025 than in 2015. Some of the most significant increases were seen in popular destinations known for their scenic night skies, such as Leh in Ladakh, Shimla, Jaisalmer, Manali, and Rishikesh.
The project has received 1,198 photographs from more than 490 contributors across 63 countries, with India being its third-largest source of observations after the United States and China. Suhani's work serves as a reminder of the importance of understanding and addressing light pollution in our urban landscapes.