Globe at Night

The coordinating researchers compile this information to produce a public, freely available map of global light pollution.

Exposure to artificial light can prove fatal for some organisms (e.g. moths that fly into a burning flame), can interrupt a life cycle phase for others (e.g. glowworms are unable to attract mates), and can reduce the possibilities for finding food (because of increased risk of predation).

Skyglow prevents large fractions of the Earth's population from viewing the Milky Way,[6] which drove the development of much of ancient science, mythology, and religion.

[1][8][9] The project asks members of the public to go outside on dark moonless nights and report how many stars are visible in particular constellations.

[8][10][12] The choice of a two-week span of dates near the new moon removes any effect on sky brightness from scattered moonlight, and observing well after sunset prevents any lingering light from twilight.

Assuming normal visible acuity and clear skies, it is possible to approximately convert Globe at Night naked eye limiting maximum estimates into other units:[26] The Globe at Night project was launched as a NASA program in the United States.

Data from the Globe at Night program has also been used in a study of the effects of artificial lighting on the foraging habits of bats.

Artificial lights attract many insects, to the advantage of some spiders, as on this lighted bridge over the Loire River , France. These changes in behavior can then affect food webs and cause further knock-on effects .
The visibility of the constellation Orion varies depending on the observer's local level of light pollution; clear sky is on left, light-polluted sky is on right. Note that the photo at left shows more detail than can be seen with the human eye.
When Globe at Night observations are averaged together, they are very strongly related to the sky brightness in the location. This is a single panel from this image .
Locations of Globe at Night observations from 2009–2011.