Visible Infrared Imaging Radiometer Suite (VIIRS)-the first satellite instrument to make quantitative measurements of light emissions and reflections-detects photons of light reflected from Earth's surface and atmosphere in 22 different wavelengths. These beautiful images show how humans have shaped the planet and lit up the darkness. Satellite images of Earth at night have always triggered curiosity among people and they are also an important tool for economic, social science and environmental research projects. Using technology provided by Google, Proville and his co-authors were able to go deeper - crunching the numbers on 21 years of data at a granular level and examining the correlations between light and eight major variables, including population, emissions and poverty.The National Aeronautics and Space Administration (NASA) scientists have just released the first new global map of earth at night since 2012, providing a clear and composite view of the patterns of human settlement across the Earth.

Based on this trove of satellite data, Proville and fellow researchers were able to demonstrate that a nation’s nocturnal glow is a powerful predictor of a wide variety of demographic, economic and industrial indicators.ĭue to the staggering gigabytes of data that are publicly available from government satellites, most previous efforts to correlate nighttime lights with variables like a region’s economy have been limited to a few years of data or a handful of countries. Countries might report economic or industrial progress in different ways, using different methods of measurement or even cooking the books for better headlines, but the amount of light they emit is gauged the same way from every spot on Earth.

While it makes for a pretty picture, data on how much light a place emits at night is also valuable when it comes to geopolitics, thanks to the unadulterated democracy of studying light from space.

Night satellite view of earth