ALT A red and blue map of the world. The colors represent the amount of heat radiating away from Earth, as measured by satellite. Red colors indicate warm temperatures, and the blue areas are clouds. This is called “brightness temperature.” Most of the map is light red. The southwestern United States, northern Africa, the Arabian Peninsula, and much of Asia are dark red. The image was captured by the NASA/NOAA Suomi NPP satellite on July 5, 2023.