LED lights are praised for their low power consumption. But are they making the light pollution worse?
A project called ‘Cities at Night’ is using photographs clicked by astronauts from the International Space Station (ISS) to map nightly light pollution in cities around the world. The project, which started in April 2014, is cataloguing over 130 000 high-resolution images. The main idea behind it is to understand the amount of light being produced in cities and to highlight the sources of light pollution. Scientists from the Universidad Complutense de Madrid, Spain, the Cégep de Sherbrooke in Canada and International Astronomical Union (IAU), who are running the project, relied on crowdsourcing to help map the images and classify them. The photos are available onwww.citiesatnight.org .
Here are some photos showing the light pollution in some major cities.
One big surprise emerging from this entire exercise is that light-emitting diodes (LEDs) street lights, which are much praised for their energy-saving capabilities, are actually making maximum light pollution. “The new results confirm that this diffuse glow, which is seen from space, is scattered light from streetlights and buildings. This is the component responsible for the brightening of the night skies in and around cities, which drastically limits the visibility of faint stars and the Milky Way,” says the official statement of the IAU released on Tuesday.
This the first time there is reliable data to illustrate the amount of light pollution across cities globally. Perhaps, this could be vital for researchers working on methods of improving lighting around cities.
