### Earth at Night 2012

This new global view and animation of Earth's city lights is a composite assembled from data acquired by the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite. The data was acquired over nine days in April 2012 and thirteen days in October 2012. It took satellite 312 orbits and 2.5 terabytes of data to get a clear shot of every parcel of Earth's land surface and islands. This new data was then mapped over existing Blue Marble imagery to provide a realistic view of the planet.

### Light Pollution

Light pollution, also known as photopollution or luminous pollution, is excessive or obtrusive artificial light. Pollution is the adding-of/added light itself, in analogy to added sound, carbon dioxide, etc. Adverse consequences are multiple; some of them may be not known yet. Scientific definitions thus include the following:

- Degradation of photic habitat by artificial light.
- Alteration of natural light levels in the outdoor environment owing to artificial light sources.
- Light pollution is the alteration of light levels in the outdoor environment (from those present naturally) due to man-made sources of light. Indoor light pollution is such alteration of light levels in the indoor environment due to sources of light, which compromises human health.
- Light pollution is the introduction by humans, directly or indirectly, of artificial light into the environment.

Recommended Links:

- Official NASA Release
- Light Pollution

Text based on Wikipedia,
License: CC-by-SA 3.0
License of the map: Public Domain