Christmas lights - as seen from space
Photo: NASA Goddard Photo and Video
May your days be merry and bright, people will be singing all over the Earth this Christmas, but the planet literally does become bright, according to new photos from NASA, which reveal that the billions of tiny fairy lights we put up every December are visible from space.
The pictures come from the NOAA/NASA Suomi National Polar-orbiting Partnership (Suomi NPP) satellite, which has compared major cities in the US at Christmas and New Year to the rest of the boring, non-fairy-light-related calendar.
According to their readings (through VIIRS - that's "Visible Infrared Imaging Radiometer Suite"), all those light bulbs add up to one big difference, as nighttime lights shine 20 to 50 per cent brighter during Christmas and New Year's when compared to light output during the rest of the year.
VIIRS can observe the dark side of the planet – and detect the glow of lights in cities and towns worldwide. Filtering out clouds, moonlight and airborne particles, scientists managed to isolate city lights on a daily basis, allowing them to track when exactly people illuminate the night - and how brightly their lights shine.
In the United States, the lights started getting brighter on Black Friday, the day after Thanksgiving, and continued through New Year's Day, explains Miguel Román, a research physical scientist at NASA Goddard and member of the Suomi NPP Land Discipline Team, who co-led this research.
In most suburbs and outskirts of major cities, light intensity increased by 30 to 50 percent. Lights in the central urban areas did not increase as much as in the suburbs, but still brightened by 20 to 30 percent.
One city where the nights are definitely a lot brighter this Christmas is Newark, California, where one homeowner has crafted a Christmas light show that is synchronised to music from Star Wars.
The show uses around 100,000 lights, but the display is designed to raise money for the poor and homeless through his church, which has stopped any angry neighbours pulling the plug.
The daily reading of nighttime lights is a new way to look at society and energy consumption, adds NASA, as scientists and policy makers need to better understand the driving forces behind energy use, including cultural behaviour.
"It's a near ubiquitous signal. Despite being ethnically and religiously diverse, we found that the U.S. experiences a holiday increase that is present across most urban communities," Román adds. "These lighting patterns are tracking a national shared tradition."
The trend can be observed at one other time of year, though: in some Middle Eastern cities, nighttime lights shine more than 50 per cent brighter during Ramadan too.
Now, back to Star Wars...