A massive sunstorm on 4th August 1972 may have scuppered a major US Navy operation in Vietnam by exploding hundreds of mines.
Operation Pocket Money, a plan to deploy 11,000 sea mines off the coast of North Vietnam to cut off naval supply routes to the region, was hit by the detonation of dozens of mines in a strange event.
Now, a new study says extreme space weather could have caused the explosions south of Hai Phong, North Vietnam.
Researchers say the solar storm activated magnetic sensors in the undersea destructor mines, causing them to blow up en masse.
The underwater explosives were rigged to detonate in response to magnetic, acoustic, and pressure signatures from passing ships.
However, on August 4, 1972, crew members aboard U.S. Task Force 77 aircraft suddenly observed explosions south of Hai Phong.
20 to 30 explosions were documented in just 30 seconds.
Another 25 to 30 patches of muddy water were also observed, indicative of further explosions.
‘The extreme space weather events of early August 1972 had significant impact on the US Navy, which have not been widely reported,’ researchers led by Delores Knipp, a space weather expert at the University of Colorado at Boulder, said in their paper.
‘These effects, long buried in the Vietnam War archives, add credence to the severity of the storm: a nearly instantaneous, unintended detonation of dozens of sea mines south of Hai Phong, North Vietnam on 4 August 1972.’
The largest solar storm ever recorded, The Carrington Event in 1859, took out telegraph machines across the US, purportedly causing sparks to fly from equipment – some bad enough to set fires inside offices.
The team concluded that the 1972 event could have been in the same league as the Carrington Event.
‘The activity fits the description of a Carrington‐class storm minus the low latitude aurora reported in 1859,’ they wrote.
‘In our view this storm deserves a scientific revisit as a grand challenge for the space weather community, as it provides space‐age terrestrial observations of what was likely a Carrington‐class storm,’ the authors said.
NASA describes the storm as ‘legendary’ because it occurred in between two Apollo missions: the crew of Apollo 16 had returned to Earth in April and the crew of Apollo 17 was preparing for a moon landing in December.
It says a moonwalker caught in the August 1972 storm might have absorbed dangerous levels of radiation, forcing them to return to Earth immediately for treatment.
The US Navy attributed the dramatic event to ‘magnetic perturbations of solar storms.’