In 1967 the U.S. Air Force was ready to send nuclear-armed aircraft to bomb the Soviet Union.

The date was May 23, and radar systems built to detect incoming missiles had been disturbed. Military commanders assumed that the Soviets had pushed the red button, and prepared to respond in kind.

Solar Flares
Image source: Wikimedia Commons

Air Force almost scrambled nuclear-armed aircraft

However before any missiles were launched, Air Force command was ordered to stand down following news from the newly-opened Solar Forecasting Center. The facility had discovered the real reason behind the radar disruption: powerful solar flares.

The frightening story of a close call has been revealed in a new military history paper, which details just how close the solar flares came to causing nuclear war.

“This is what we would characterize as a really near miss,” said lead author Delores Knipp, a former Air Force officer and space weather physicist at the University of Colorado, Boulder

Solar activity luckily subject to research

Solar flares can cause radio devices to go dead, and the accompanying coronal mass injection can cause impressive aurora borealis activity and cause huge power outages on Earth. These are the most severe consequences of solar flares.

While any changes are only temporary, the problems can worsen rapidly if people don’t understand what is going on. This was the case in 1967.

Scientists had just started paying more attention to solar activity, and on May 18 observers saw a group of sunspots come together on the surface of our star. On May 23 a number of bright solar flares were observed and photographed, before predictions of a worldwide geomagnetic storm were made.

Nuclear catastrophe averted

The predictions came just as the Air Force was placing more aircraft on “ready to launch” status, after the Ballistic Missile Early Warning System (BMEWS) went dark. The radar system is the kind of technology that is particularly susceptible to space weather.

Luckily the prediction of a solar storm reached the high levels of command just in time.

“The aircraft did not launch—we’re pretty certain of that,” Knipp said. “Was war imminent? What we know is that decisions were being made on the tens of minutes to hours basis, and that information got to the right place at the right time to prevent a disaster.”

Around 40 hours later a geomagnetic storm hit Earth and affected radio communications. It also set off the northern lights for around a week, as far south as New Mexico.

Extreme space weather could be very dangerous for life on Earth, even if nuclear war is not triggered. The largest geomagnetic storm hit our planet in 1859, and is known as the Carrington Event. If a storm of a similar size hit Earth today, it could knock out transformers around the world and leave billions off people off grid for weeks if not months.

As proven by the 1967 incident, it is important that we understand space weather and how it can affect technology on Earth. Luckily the nuclear missiles were not launched in May 1967, and the storm in fact inspired further research into space weather.

Some of the forecast tools we have today were developed in the aftermath of that event, but further study is needed to make sure that we are as prepared as possible for any future geomagnetic storms. Luckily the U.S. was taking an interest in space weather before the 1967 event, but even greater understanding is needed today.