This video provides a synopsis of NASA’s latest Sun-sensing initiative, EVE -- Extreme ultraviolet Variability Experiment. The EVE project tracks changes in the Sun’s extreme ultraviolet energy output. Extreme ultraviolet, as the name implies, is light that’s within the ultraviolet band but at the higher-energy range. By tracking data over many years, scientists will be able to better understand the Sun’s 11-year activity cycle and will collect important data by which to assess whether the Sun’s energy output is slowly decreasing, as some theories would suggest.