From UPSC perspective, the following things are important :
Prelims level : Light pollution
Mains level : Light pollution and its ecological impact
Objects sent to space that orbit the Earth can increase the overall brightness of the night sky by 10 per cent above natural levels, showed a new study.
- Light pollution is the presence of anthropogenic and artificial light in the night environment.
- It is exacerbated by excessive, misdirected or obtrusive use of light, but even carefully used light fundamentally alters natural conditions.
- Specific categories of light pollution include light trespass, over-illumination, glare, light clutter, and skyglow.
- A single offending light source often falls into more than one of these categories.
How does a satellite contribute?
- Large fleets of communication satellites that have been unleashed in space not just add to the light pollution but also collide and form more debris.
- Light from this piling debris cloaks astronomical bodies like ‘the glowing clouds of stars in the Milky Way’ from human sight.
- While telescopes and sensitive cameras often resolve space objects as discrete points of light, low-resolution detectors of light such as the human eye see only the combined effect of many such objects.
- Astronomers have complained that the growing number of artificial space objects choke the sky and disturb observations.
Impacts of light pollution
- As a major side-effect of urbanization, it is blamed for compromising health, disrupting ecosystems and spoiling aesthetic environments.
- Health effects of over-illumination or improper spectral composition of light may include increased headache, worker fatigue, medically defined stress and an increase in anxiety.
- Likewise, animal models have been studied demonstrating unavoidable light to produce adverse effect on mood and anxiety.
- For those who need to be awake at night, the light at night also has an acute effect on alertness and mood.