Using a new sensor aboard a joint NASA-NOAA satellite, scientists now can observe Earth’s atmosphere and surface during nighttime hours, and the sensor is able to capture exceedingly low light — like the glow from a single ship at sea. The latest data was used to make a composite film of the entire planet at night. Unlike a camera that captures a picture in one exposure, the day-night band detector on the sensor produces an image by repeatedly scanning a scene and resolving it as millions of individual pixels. Then the day-night band reviews the amount of light pixel by pixel.
With its night view, the satellite is able to detect a more complete view of storms and other weather conditions, such as fog. Or, as in the case of the composite image, no weather at all, since this is a combination created above clear skies all over the world and then stitched together into a cohesive whole. Sick, huh?