On July 9 , 1962 , crowds gathered on the beaches of Honolulu , Hawaii , and watch out as the US detonated a atomic bomb calorimeter in outer infinite .
Known as Starfish Prime , the explosion was part of a serial of gamy - altitude nuclear tests known pretty innocuously as " Operation Fishbowl " . Five atomic devices were set off during the mental test , with Starfish being the largest atapproximately 1.4 megatons(the equivalent in term of vim firing of 1.4 million oodles of TNT being detonated all at once ) .
After the bomb was blow up some 400 kilometers ( 249 stat mi ) above Johnston Island in the Pacific Ocean , and auroras were seen across the sky as electronics began to conk out .
The blast, as viewed from Honolulu. Image credit:Public domain/US Military
" At Kwaialein , 1400 mile to the west , a thick overcasting extended the duration of the easterly horizon to a pinnacle of 5 or 8 degrees , " one eyewitness of the event state , asrecorded in a military report .
" At 0900 RC a bright white flash burned through the cloud rapidly changing to an expanding greenish formal of irradiance extend into the clear sky above the cloud cover . From its surface extruded great white-hot finger , resemble cirro - stratus clouds , which rose to 40 grade above the visible horizon in sweeping arcs twist down toward the poles and disappearing in seconds to be replaced by spectacular homocentric cirrhus like rings moving out from the blast at tremendous initial speed , finally hold back when the outermost band was 50 arcdegree overhead . "
" They did not disappear but prevail in a state of frozen lifelessness . "
" As the dark-green light turned to purpleness and began to fade at the distributor point of flare-up , a bright red freshness began to build up on the horizon at a direction 50 degrees north of east and at the same time 50 degree south of Orient expanding inward and upward until the whole easterly sky was a boring burning red semicircle 100 degree northward to south and halfway to the zenith obliterating some of the lesser star . This stipulation , interspersed with fantastic white rainbows , remain no less than seven minutes . "
The run – almost certainly aresponse to similar Soviet tests – were design in part to test the issue on the Earth ’s magnetic battleground , and whether atomic explosion in space could be weaponized against the Soviets . They found , to their surprisal , that it was efficacious at shutting down several orbiter , include one set in motion the Clarence Day after the test that were hit withhigher than expect level of radiation .
" Some electronic and electric systems in the Hawaiian Islands , 1400 kilometers distant , were affected , cause the nonstarter of street - lighting systems , tripping of tour breakers , set off of burglar warning machine , and damage to a telecommunication relay facility , " areport in 2012 noted .
" What is significant about an EMP attack is that one or a few in high spirits - altitude nuclear detonation can produce EMP effect that can potentially disrupt or damage electronic and electrical system over much of the United States , virtually at the same time , at a time watch by an adversary . "
The effect of the trial run – consider in " rainbow parties " below – lasted longer than the pretty sunrise . An contrived radiation belt was create by the gust , with levelshigher than the naturally - fall out Van Allen belts , that lasted for several age .
