Beguilingly beautiful: Scenes of city lights, like this one of San Francisco Bay, might be pretty, but they're also a reminder of how light pollution can cloud our view of the stars.
Credit: Thomas Hawk
SYDNEY: Scenes of city lights, like this one of San Francisco Bay, might be beautiful, but they're also a reminder of how light pollution can cloud our view of the stars.
As urban light pollution grows as a problem, a global survey now aims to map its spread, with the help of amateur star gazers.
The Great World Wide Star Count is an international project which pools skyward observations taken by citizens around the world. The information helps scientists measure the extent to which city lights mask the visibility of stars.
The project, in its second year, is organised by the University Corporation for Atmospheric Research, (UCAR) a consortium of 70 universities and the U.S. National Centre for Atmospheric Research.
Citizen science
In 2007, more than 6,600 observers on all seven continents took part. From the data, UCAR created maps of star visibility around the world.
"Last year's results showed a strong correlation between dense development, where there is a lot of light, and a lack of star visibility," said Dennis Ward of UCAR's Office of Education and Outreach. "Without even being aware of it, many of us have lost the ability to see many stars at night."
Participants in the northern hemisphere will look for the constellation Cygnus, while those in the southern hemisphere will turn their attention on Sagittarius. By focussing on particular constellations, sciences can more accurately compare how star visibility differs around the world.
Participants can download forms from the website. People encountering cloudy weather can record their observations of the clouds instead. This year the survey runs from 20 October until 3 November.
