The world may have come closer to the brink of nuclear disaster than previously thought after a 1967 solar storm jammed radar and radio communications at the height of the Cold War, according to new research.
The largely unknown incident could have led to a disastrous military conflict if it had not been for the US Air Force’s budding efforts to monitor the Sun’s activity, claims the study by the University of Colorado.
On May 23, 1967, the Air Force prepared aircraft for a possible nuclear attack, thinking the nation’s surveillance radars in polar regions were being jammed by the Soviet Union.
A potentially deadly catastrophe was narrowly averted when military space weather forecasters warned that radar and radio communications could be disrupted by the solar storm, resulting in the planes being stood down.
Retired US Air Force officers have described the incredible events for the first time in a paper published in the American Geophysical Union’s journal Space Weather.
“Had it not been for the fact that we had invested very early on in solar and geomagnetic storm observations and forecasting, the impact [of the storm] likely would have been much greater,” said Delores Knipp, a space physicist at the University of Colorado in Boulder and lead author of the new study.
“This was a lesson learned in how important it is to be prepared.”
The US military began monitoring solar activity and space weather in the late 1950s. By the 1960s, a new Air Force branch – the Air Weather Service (AWS) – was monitoring the Sun for solar flares.
These solar flares are brief intense eruptions of radiation from the Sun’s atmosphere and can lead to electromagnetic disturbances on Earth than can disrupt radio communications.
A major solar flare on 23 May 1967 caused radars at all three Ballistic Missile Early Warning System (BMEWS) sites in the far Northern Hemisphere to become jammed.
Any attack on these stations, including signal jamming, was considered to be act of war.
Using information from the North American Aerospace Defense Command’s Solar Forecast Centre, forecasters worked out that it was the Sun that was blocking the signals, and not the Soviets.
As a result, the potential deployment of nuclear weapons was halted, says the new report.
Study author Delores Knipp notes that the information about the solar storm was probably not relayed to high-level government officials, including President Lyndon B. Johnson.
It was the military’s correct diagnosis of the solar storm that prevented the event from becoming a disaster, says the study.
The near-miss led the the US military to recognise the importance of space weather and to build a stronger forecasting system.