The United States has experienced disruptions from electromagnetic pulses (EMP) due to high-altitude hydrogen bomb explosions and also space weather. The first time that this occurred with the hydrogen bomb was the starfish test detonation experiment. This explosion was over 800 miles away from Hawaii, and it still disrupted many electrical devices. Solar storms also create EMP events that upset these devices. These storms come about from solar flares and coronal mass discharges from the sun.