Mines like these, deployed in waters off the coast of Vietnam just 3 months earlier, suddenly detonated without explanation in August 1972. The event was attributed to “magnetic perturbations of solar storms.” Credit: U.S. Navy
In 1972, during the waning years of the Vietnam War, U.S. military pilots flying south of Haiphong harbor in North Vietnam saw something unexpected. Without explanation and without warning, over two dozen sea mines suddenly exploded.
Although the phenomenon was never officially explained, it piqued the interest of geospace scientist Delores Knipp.
Knipp is a research faculty member at the Ann and H. J. Smead Aerospace Engineering Sciences Department at the University of Colorado Boulder and editor in chief of the AGU journal Space Weather.