Dark Sky and Light Pollution

Dark sky refers a night sky which is free from light pollution. The light pollution is a type of pollution caused by abundant use of artificial light sources at night. We all convinced that light pollution is increasing day by day across the world especially in urban cities. Due to heavy use of light like streetlight, lights from buildings the night sky is not seen as dark. In short; the excessive use of artificial light in nighttime is called as light pollution. The light pollution caused so many negative effects in environment, in human health, in ecosystem, and in biodiversity. From astronomical perspective, light pollution highly disturbs astronomers to observe the sky. Some consequences of light pollution are ;

(a) Light pollution obstructs astronomers a lot. To observe the astronomical bodies through telescope they need dark night otherwise there will be reduction in the visibility of the stars or other celestial bodies. Due to lack of visibility, they cannot able to observe the celestial objects clearly.

(b) There can be disturbance in ecosystem and biodiversity. For example, light pollution may disturb the livelihood of animals, birds or other organisms. In long run this may cause migration of animals from such light polluted places to other. Light pollution may also leads to climate change.

(c) Light Pollution can cause several side effects in human health like sleep disorders, fatigue, depression, and others.

(d) Light pollution is caused by using artificial light sources which consumes large amount of energy. So we can say there is waste of energy also.

(e) It really affects astrophotographers in taking beautiful images of space events. It affects the field of Astro tourism.

Ways to reduce light pollution can be;

(a) We can use some shielders to force the light to fall in downward (towards ground). We can use energy efficient light source which can produce light of less scattering.

(b) We can aware the people about the side effect of light pollution and importance of dark sky for the humanity as well as for our ecosystem.

(c) By following the policies about the dark sky. “International Dark Sky Association (IDA)” is the prime organization for the policy formulation about dark sky.

Conclusion: We all need to understand about the negative effects of light pollution as well as to know the significance of dark sky. We should not have to use unnecessary artificial light sources. Maintaining dark sky also leads to calm and cool environment. Dark sky has several advantages in maintaining the biodiversity in our planet.

By: Prem Raj Joshi

Lecturer of Physics at Kailali Multiple Campus, Dhangadhi, Kailali, Nepal