# facts | How a solar flare nearly caused a nuclear war

May 23, 1967 could be the day nuclearwar. On this day, the U.S. Air Force was ready to put into action loaded tactical nuclear bombers. It all started with the fact that radar systems designed to track Soviet ballistic missiles were completely disabled. The event is considered by the military as an act of aggression. And then there's the cold war! Fortunately, before the nuclear bombs were fired, the U.S. Air Force was released.

American just built at the timeThe Solar Activity Monitoring Center was able to explain the true cause of the massive breakdown of radar equipment. This reason turned out to be a series of powerful solar flares. At least that's what the recently declassified military historical document says, describing how mankind nearly destroyed itself due to the oddities of space weather.

“This is what it says:“ it’s carried, it’s gone! ”Says Delores Knipp, a former US Air Force officer and an employee of the Department of Space Weather at Colorado University in Boulder.

Space weather - a term encompassing inbroadly, the most practical aspects of the science of solar-terrestrial relations. Most often, solar activity is implied here, which begins with solar flares, as well as powerful x-ray and ultraviolet emissions into space. When a solar flare reaches the upper limit of our atmosphere - the ionosphere - it begins to behave like an electromagnetic pulse, an electric discharge of destructive force, burning all the electronics around.

Thomas Berger, director of the Space Weather Forecasting Center, comments:

“Radio communications still sometimes suffer fromsimilar phenomena. Transmitting radio messages over the horizon becomes difficult. When, for example, airplanes fly over the poles, the only means of communication with the control center are microwave radio waves. But this is only a temporary difficulty, lasting from 10 minutes to several hours in the worst case. ”

Following the main flare, the sun is usuallyproduces a giant cloud of magnetized plasma, which is called the coronal mass ejection. This slowly moving “bubble” of stellar material takes from 12 hours to several days to reach the Earth, however it is it that causes the most serious consequences of the manifesting solar activity, starting from the northern lights and ending with large-scale interruptions in the operation of electric networks.

According to Berger, space weather, tofortunately, is temporary. However, it can cause more serious problems if people in power do not understand what is really happening. This happened during the "great solar storm" in May 1967. At that time, the US military was just beginning to constantly monitor solar activity with the equipment of the Air Force’s aerometeorological service, which provided daily reports to weather forecasters at NORAD (North American Aerospace Defense Command).

View of the Sun on May 23, 1967 in the narrow visible range of H-alpha. Bright spots in the sun's image indicate the epicenter of the appearance of solar flares

By May 18, 1967, observers discoveredseveral sunspots concentrating on one area of ​​the sun’s surface. At noon on May 23, a series of solar flares were noted and photographed, including one that will later be considered by scientists as the largest solar radio flash of the 20th century. Shortly after the outbreaks were discovered, the NORAD Solar Activity Monitoring Center sent a message to headquarters about an approaching giant geomagnetic storm, which would reach Earth within the next 36-48 hours.

However, this forecast came late. As a result, the outbreak of a geomagnetic storm "put on the ears" of the Air Force, when a failed ballistic missile early detection system (BMEWS) forced the command to order the preparation for the launch of nuclear weapons.

Used at that time of the cold war andthe radar system operating in the far northern latitudes became a textbook example of technologies that can be disabled as a result of space weather. According to Knipp and her co-authors, some of whom are retired U.S. Air Force officers and close to the events described today, this delay in transmitting information to the Solar Activity Monitoring and Prediction Center almost became the cause of the onset of a global nuclear disaster.

“None of the missiles were launched. We know this for sure, ”says Knipp.

“Was war inevitable? As far as we know, the decision took from tens of minutes to several hours, and ultimately the space weather forecast obtained at the right place and right time could prevent this global catastrophe. ”

After about 40 hours, the main geomagnetic storm reached the Earth, brought out radio communications and then still lit up by the northern lights up to the state of New Mexico for almost a whole week.