Madhur Tankha

Light pollution is harmful to nocturnal life forms

Deprives city of a chance to view night sky

NEW DELHI: India does not have a good report card so far as light pollution is concerned. Besides posing a health hazard and being harmful to nocturnal life forms, light pollution also deprives urban dwellers of a chance to view the night sky lit up by stars.

Nehru Planetarium Director N. Rathnasree, who is studying levels of light pollution in India, says people need to ponder over this important issue and take corrective action.

“Air and water pollution have a more immediate impact on human health. However, by paying attention to light pollution we would also be addressing the possibility of a more efficient use of energy for outdoor lighting that in turn will address the issue of diminishing energy resources.”

The Nehru Planetarium Director says: “Some of the damage can be reversed with timely action. Knowing the pollution level quantitatively might also help us fight it better. The extent of light pollution can be studied through satellite imagery. However, translating from there to the question of actual sky brightness as seen from the ground involves a lot of estimation of unknown factors like aerosol content over different regions.”

She says that to make an estimate one has to count the number of stars visible in a very specific region of the sky: “These are bound by relatively bright stars. One needs to learn one’s way around the sky. And then one can simply count the number of stars in a given region and submit this data to a pool of data being collected.”

A collaborative venture in this direction is the “Taare Sadak Par” programme of quantifying light pollution. Many institutions, students and amateur astronomers have started making significant contributions to the same. Some of the organisations contributing to this project are Nehru Planetarium, Science Popularisation Association of Communicators and Educators and Astro Education Services.