Three years ago, a satellite called Suomi NPP, a joint mission between NASA and the National Oceanic and Atmospheric Administration, began recording images of Earth from space.
Now a NASA-led team has decided to take a closer look at how the light Earth gives off changes over a year.
When we started looking at the data at night over the United States, we were expecting to see a lot of stability in the night time lights. We were surprised to see there is a vibrant increase in activity during the holidays, particularly around areas in the suburbs.
Between Thanksgiving and New Year's Day, major US cities put out 20–50% more light than they do in the rest of the year.
The biggest increase, up to 50%, happens in the suburbs. But city centres can increase their output by up to 30%.
It's not just Americans getting in on the holiday light-show. Some Middle Eastern cities shine up to 50% brighter during Ramadan.
So if you think all those Christmas lights are obnoxious, now you have a NASA-backed excuse when asking your neighbour to tone it down a bit.
