Astrophotography, which involves taking photos of the night sky, allows us to capture the sky in its true nature and complexity, revealing more details of stars and celestial bodies. To capture a clearer sky, we had to move away from artificial lights, as they obscure the brightness of the stars and the Sky itself. Therefore, we made stops every 50 km heading north of Brasilia, towards the outskirts of Alto Paraíso de Goiás, finishing at the 200 km mark from Brasilia.

Light pollution is the excess or misuse of artificial lighting that interferes with the visibility of the night sky. This phenomenon occurs mainly in urban areas, where artificial lighting, such as streetlights, cars, billboards, and other light sources, creates a glow that obscures the view of stars and other celestial bodies.

The improper use of public lighting and other light sources contributes to light pollution, especially when light is directed upwards or to areas that do not need illumination. Although LED lights, currently used, are more energy-efficient, their improper vertical use intensifies the glare of the night sky, obscuring the view of stars. This incorrect direction of lighting not only wastes energy but also directly interferes with the ability to observe the Sky, erasing its natural beauty and disturbing the balance of nocturnal ecosystems.

Light pollution influences your electricity bill and the public lighting tax you pay. Inefficient and poorly directed lighting wastes energy, which increases costs for both taxpayers and municipal governments. In Brazil, the NBR 5101 standard regulates public lighting and defines the minimum requirements for the proper installation of lighting systems to minimize light pollution. It is important for this standard to exist, make sense, and be followed. This would help reduce waste and improve energy efficiency, resulting in savings for everyone and preserving the night sky.

How to reduce Light Pollution?

There are several practical ways to reduce light pollution. For example:

• Use streetlights that direct light only where it is needed, preventing it from spreading upwards or sideways;
• Implement motion sensors so lights are only turned on when there is activity, reducing unnecessary lighting time;
• Adjust light intensity to appropriate levels, avoiding excessive brightness and energy waste;
• Use LED bulbs with a warmer color temperature (more yellow) to reduce environmental impact and light dispersion;
• Follow the NBR 5101 standard to ensure public lighting is designed to minimize light pollution;
• Install timers to turn off lighting during periods of low activity or overnight;
• Raise awareness among companies responsible for public lighting about the importance of reducing light pollution and encourage responsible lighting practices;
• Create protected zones against light pollution in environmental protection areas.

The night sky should be recognized as a world heritage due to its historical, scientific, and cultural significance. Since ancient times, humanity has been guided by the stars for navigation, agriculture, and the development of mythologies and religions. Since 2016, the UNESCO has defined the night sky as a natural heritage, as we understand its invaluable value for science, such as in astronomy and space discoveries. Preserving the night sky is protecting a universal resource that enriches the human experience and preserves our cultural heritage.