Wikipedia
Photoflash bomb
thumb|Flashbombs being loaded into aircraft.
A photoflash bomb, or flash bomb, is explosive ordnance dropped by aircraft, usually military surveillance aircraft, designed to detonate above ground to create an extremely bright flash of light. These bombs, which are capable of producing light at an intensity of up to several million candlepower, assist surveillance aircraft in taking nighttime aerial photos without the need to fly low to the ground which would make it vulnerable to possible enemy detection. Due to the advent of better nighttime optics, satellite imagery, and stealth aircraft, these bombs are no longer used by the military.