Much to the dismay of dark sky enthusiasts everywhere, humanity's efforts to divorce itself from the night and encase civilization in lamp light appear to be accelerating.
For the first time in five years, NASA has released an updated, high-definition composite map of the Earth under darkness. Nicknamed the "Black Marble," the map shows a world increasingly defined and pockmarked by the glow of nighttime lights.
The data was collected by the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite using an advanced instrument called the Visible Infrared Imaging Radiometer Suite (VIIRS). Thanks to a special low-light sensor, VIIRS is able to capture photons of light reflected from Earth's surface and atmosphere in 22 different wavelengths.
"VIIRS is the first satellite instrument to make quantitative measurements of light emissions and reflections, which allows researchers to distinguish the intensity, types and the sources of night lights over several years," reports NASA.
Despite this advanced eye in the night sky, capturing these images is still a challenge. In order to produce the new maps, which include the highest definition night scenes ever photographed, a NASA team has to account for both moonlight, seasonal vegetation, snow and ice cover, and even atmospheric glow for phenomenon such as auroras.
The new filtering techniques developed by the researchers may soon allow Suomi NPP to observe light as faint as a country road lamp or a lone fishing boat. The team is also automating the process so that images from the civilian science satellite will be made freely available to scientists within minutes to hours of acquisition.
"Thanks to VIIRS, we can now monitor short-term changes caused by disturbances in power delivery, such as conflict, storms, earthquakes and brownouts," said team leader and Earth scientist Miguel Román of NASA’s Goddard Space Flight Center. "We can monitor cyclical changes driven by reoccurring human activities such as holiday lighting and seasonal migrations. We can also monitor gradual changes driven by urbanization, out-migration, economic changes, and electrification. The fact that we can track all these different aspects at the heart of what defines a city is simply mind-boggling."
Naturally, VIIRS is also allowing researchers to better track the growing creep of light pollution across the planet. In June 2016, researchers at the Light Pollution Science and Technology Institute in Thiene, Italy, released an atlas of light pollution based on data collected by the Suomi NPP satellite.
The data paints an alarming picture of blues, yellows, reds, and whites –– with few dark spots in the U.S. left. According to the study, 80 percent of the world and more than 99 percent of the U.S. and European populations live under light-polluted skies. One-third of the world and 80 percent of North America cannot witness the Milky Way.
“A starry sky is something that touches your soul,” lead author Fabio Falchi told Scientific American. “Our civilization’s religion, philosophy, science, art and literature all have roots with our views of the heavens, and we are now losing this with consequences we cannot fully know. What happens when we cannot be inspired by the night sky?”