Explosives going off without warning is bad news for … well, for everybody . So imagine the U.S. military's alarm…
Explosives going off without warning is bad news for … well, for everybody . So imagine the U.S. military’s alarm when, on August 4, 1972, it witnessed about two boxes or so spontaneous explosions in the waters off Hon La in North Vietnam. America’s Operation Pocket Money had dropped underwater mines there many weeks before to deter trade ships from venturing to North Vietnam ports. Men de mines var kun ment til at detonere, når skibe var omkring, og amerikanerne overvågede vandet fra overhead var kun ser klarblå når bomberne gik.
Initially, the explosions were inexplicable. What could have possibly set the mines off? Big marine animals? Equipment malfunctions? Were the North Vietnamese using a secret strategy to blow up the mines remotely?
About four and a half decades later, we now know the culprit was the sun. Space Weather a powerful solar storm likely triggered the mines’ magnetic sensors and caused them to explode.
“It was a storm of magnificent proportions,” says Delores Knipp , a space weather researcher at the University of Colorado, Boulder and the lead author of the new paper. “It was a big story back in the day, and continues to be a big story.” The storm occurred between Apollo missions 1
6 and 17, but it’s generally accepted that the radiation dose would have been disabled (if not outright killed) astronauts traveling to and from the moon. In addition, other studies on the solar storm found the resulting geomagnetic current created many different power fluctuations in North America. “It’s been a storm that has been known for different effects in different communities.”
On that day in 1972, over the course of 30 seconds, American troops flying near North Vietnam witnessed between 20 and 25 explosions in the water along with an additional 25 to 30 mud spots. De miners gebruiken sensoren om te detecteren veranderingen in de omliggende magnetische velddichtheid, die zou normaal gesproken worden veroorzaakt door een schip passeren boven.
Maar iets duidelijk ging fout. Just days after the occurrence, U.S. Military officials were already wondering whether solar activity may have precipitated the detonations. At the time, the world’s scientists already knew the sun was able to produce changes in magnetic fields, but they were not certain whether solar activity reaching the Earth was powerful enough to trick the mines’ sensors. Endually, investigators working with the military and NOAA would quietly conclude solar activity was probably the blame, but the case was not completely resolved.
Armed with more a more current understanding of solar activity, Knipp and her team dug into now-declassified documents and found that the 1972 event was a uniquely strong solar storm, and several factors augmented its effects as it hit Earth.
Several hours before the bombs went off, the sun began to flare up and experienced what’s called a coronal mass ejection -A large vomit of a high-energy plasma and radiation particles that carry electromagnetic pulses along the way. Det normalt tar en dag eller to for dem som kommer til å nå jorden, men i dette tilfelle, tidligere blasts fra to dager før i hovedsak pløjet gennem interstellær medium, der fjerner hindringer og paving en poleret vei for august 4 ejection.
In fact, according to Knipp’s research, the August 1972 storm was on par with the Carrington event from 1859, one of the most powerful solar storms ever recorded. “It’s our poster child of storms,” says Knipp. “Om en storm som bad var at komme igen, så ville vi virkelig have mange problemer.” Vårt nuværende verden er immensivt tæmmet til kommunikationsinstrumenter, elektriske grids, og teknologi, der kan nemt blive fried af særligt stærke bursts eller solaktivitet.
Which asks the question: how often do storms like these occur? Underwater mines going off randomly, is already a scary opportunity to bear, but a loss of $ 40 billion a day to the U.S. economy is simply unthinkable.
There’s no straight answer to that-after all, the whole field of space weather is a work-in-progress towards this goal. For eksempel, breakthroughs in the last decade have helped illustrate how coronal mass ejections can occur in series rather than just as discrete events, which helped the team pinpoint why solar activity might be powerful enough to set off a couple of dozen underwater mines.  But Knipp says a general estimate, based on current knowledge, is that these kinds of solar storms hit Earth about once every 70 years- “often enough, we need to be thinking about what types of technologies are subject to harm in these kinds of environments. “The question is not really if a storm powerful enough to knock out the power grid and wreck our technological equipment will hit us-but when it will happen, and whether we’ll be ready in time to prepare and safeguard our infrastructure.