NASA’s new algorithm measures changes in light usage of major cities around the world.
City lights in the U.S. increased in brightness by up to 50 percent during the holiday season. Image by NASA's Earth Observatory/Jesse Allen.
For the first time, researchers are able to observe changes in light intensity and light output over time from images taken from space. Using an instrument called the Visible Infrared Imaging Radiometer Suite (VIIRS), NASA's Goddard Space Flight Center analyzed how patterns in nighttime light intensity fluctuated during the holidays in major cities. With an advanced algorithm, the VIIRS is capable of sifting through clouds, pollution and moonlight and isolating artifical city lights.