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Psychedelic skies over Chile reveal the full extent of light pollution

An image taken by astronomer Juan Carlos Munoz of the night sky above Santiago, Chile, uses optical techniques to reveal the extent of light pollution in major cities even while under lockdown

Technology 27 May 2020

THIS kaleidoscopic shot of the night sky above Santiago, Chile, was taken during the city’s lockdown and shows the extent of the capital’s light pollution.

Astronomer Juan Carlos Munoz captured the view from his balcony. He tries to infuse every urban night photo he takes with a “gritty and other-worldly” feel, he says.

For this picture, he covered a lens with a diffraction grating, an optical element that is engraved with grooves that split the light spilling from the buildings and streets into different wavelengths in vertical streaks.

The result reveals the make-up of the city’s various sources of illumination as a pattern soaring into the night sky. Sodium lamps have an orange spectra, metal halide lamps predominantly emit green, blue and violet light, while white LEDs are the brightest and emit across the visible spectrum (a good example is clearly visible just right of the centre of the photo).

Munoz says he takes such pictures to raise awareness of light pollution and hopes people can work together to illuminate cities in a more efficient way. “The night sky is a natural heritage that all citizens deserve to enjoy regardless of where they live, and therefore it must be protected from pollution, just like oceans or the atmosphere,” he says.

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Source: Humans - newscientist.com

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