[Image above] Credit: Jesse Allen, NASA’s Earth Observatory; NASA Goddard; Flickr CC BY 2.0


One of the holiday movies I watch every year, without fail, is National Lampoon’s Christmas Vacation.

You know the one. Chevy Chase as Clark Griswold, his crazy band of relatives, and a gut-busting scene involving the Christmas tree (I won’t spoil it if you haven’t seen it—but do yourself a favor and give it a view).

One of my favorite scenes in the movie involves Clark’s struggles with the Christmas lights—lights bright enough to be seen from outer space.

Credit: formaldehydepictures; YouTube

We all know that Hollywood uses cinematic hyperbole to stretch the limits of possibility, so the idea of seeing Christmas lights from high above the earth’s atmosphere is completely impossible, right? Not exactly.

One NASA researcher and his colleagues have had their eyes on the skies and have analyzed the light patterns during the darkest part of each day. Their data shows that during the holiday seasons—Christmas and New Year’s here in the U.S. and Ramadan in the Middle East—the night lights shone brighter, a whole 20–50% higher, in fact, than during the rest of the year.

The work is made possible because of the NOAA/NASA Suomi National Polar-orbitting Partnership satellite, which uses Visible Infrared Imagine Radiometer Suite (VIIRS). According to a NASA news release, the instrument can observe earth’s “dark side” and pinpoint the places where lights shine bright.

Here in the U.S., those lights are brightest beginning on Black Friday. The trend continues through January 1—New Year’s Day—when most people have taken down or are preparing to pack away their holiday gear for another year.

According to research leader Miguel Román, research physical scientist at NASA Goddard, that light increased by 30–50% in the suburbs and outskirts of the country’s major cities. Rural areas increased in brightness by 20–30%.

“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 says in the release. “These lighting patterns are tracking a national shared tradition.”

That tradition generally includes snow, at least in cities that experience it. Because of snow’s reflectivity and the way that reflectivity would skew data, snow-free cities (West Coast meccas like San Francisco and L.A. and major urban areas south of St. Louis and Washington, D.C.) were the only cities analyzed.

In the Middle East, nighttime lights were 50% brighter during the month of Ramadan—in which Muslims fast during the day—though some cities (Riyadh, Jeddah) saw increases as much as 60–100%. Conversely, some cities in Turkey saw much smaller increases, if any at all.


The dark green pixels are areas where lights are 50 percent brighter or more during Ramadan. Credit: Jesse Allen, NASA’s Earth Observatory

The NASA team hopes to use this data for far more than just analyzing the ways people do (or don’t) celebrate the holidays around the globe.

“Having a daily global dynamic dataset of nighttime lights is a new way for researchers to understand the broad societal forces impacting energy decisions,” says Eleanor Stokes, who co-led the research.

More than 70% of greenhouse gas emissions come from urban areas, says Román. “If we’re going to reduce these emissions, then we’ll have to do more than just use energy-efficient cars and appliances,” he says. “We also need to understand how dominant social phenomena, the changing demographics of urban centers, and socio-cultural settings affect energy-use decisions.”

Those decisions will likely include the data gathered by VIIRS, though it’s just one piece of the energy-mapping puzzle.

“What’s really difficult to do is to try and track people’s activity patterns and to understand how this shapes the demand for energy services,” Román says. “We can now see pieces of these patterns from space—when, where, and how often we turn on the lights.”

Check out the view from space in the video from NASA below.

Credit: NASA Goddard; YouTube