Once upon a time the nightly appearance of the star-filled sky was a part of our shared human experience. The stars inspired art, science, religion, and more. With the rise of cities and electric lighting the glow of civilization has been slowly removing the stars from our hearts and minds.
This artificial brightening of the night sky is called light pollution. Because of it two thirds of the population can no longer see our home galaxy, the Milky Way. The glow of the cities is so bright that even when viewed from space, city light far outshines starlight.
ANALYSIS: Light Pollution: Time to Turn On the Night?
The glow that now pervades the night has done more than remove the stars from the sky. It wastes energy and dollars; harms wildlife; and can cause long-term health problems.
International Dark Sky Week (IDSW) is currently underway (April 5-11). It was created to help draw attention to the widespread problems of light pollution and to the relatively simple solutions that can help to solve them. IDSW, which takes place during Global Astronomy Month, focuses not only on getting people back under the stars to see and appreciate the night sky, but also getting them to take action.
An easy way to begin is to make a simple survey of lighting around the outside of a home or business. This can reveal which lights can be improved. Fully shielded lamps put light on the ground and likely can be swapped out with new bulbs that use less energy and produce less light. Making that switch can save money on electric bills and lessen the impact to the night sky.
ANALYSIS: The Search For Extraterrestrial Polluters
An easy way to measure light pollution is to participate in GLOBE at Night, which is going on for most of IDSW. It is a simple citizen-science program that gets people out under the stars. Last year over 83,000 measurements of the night sky from 115 different countries were made for the campaign.
The International Dark-Sky Association (IDA) recently released a short film on light pollution called "Losing the Dark". It highlights how light pollution impacts all of us by clearly explaining the problems and solutions.
If that is not enough, the IDA has a lot of IDSW activities on their website, including links on how and where to find a local star party so that everybody can see some stars.
Scott Kardel is the Managing Director of the International Dark-Sky Association -- an organization that raises awareness of the growing light pollution threat to our night skies.