Dark Sky Meter

The Dark Sky Meter (available for iPhones) allows citizen scientists to contribute to a global map of nighttime light pollution.
Light pollution is a growing problem in urban environments, but now you can help scientists better understand its effects on the environment. The map is also a great help for (amateur) astronomers looking for dark skies.
By utilizing the camera built in to your iPhone, the Dark Sky Meter actually measures ‘skyglow’ and updates the data in real time.

The app also charts weather conditions and cloud cover so you can take readings at optimal times. The app is as easy to use as taking a picture, and is a fun way to learn about your night sky.

The Results are live and visible for everyone on a global light pollution map generated by the app users. Your data are shared with the Globe At Night Project and the Loss of the Night project. You can view results at http://www.darkskymeter.com (map) and download data from Globeatnight.org.