Satellites and Light Pollution

Q Why is it in News? 

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.

Q What is Light Pollution?  

• 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.

Q 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.

Q What are the 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.