Huge Solar Storm Once Almost Triggered Nuclear War Between U.S. And Russia

In May 1967, a solar storm brought the world to the brink of what could have been a nuclear war. With the sun now entering a period of increased activity as part of its 11-year solar cycle, experts have discussed whether or not we should be wary of a second such incident.

The world was in the grips of the Cold War in 1967 when the sun belched out one of the largest solar storms ever observed at the time, releasing a colossal radio burst that interfered with communication services here on Earth.

The United States military was immediately troubled by this radio interference on its radar system, which it interpreted as a deliberate jamming attempt by a foreign adversary. Such a move could have been considered a potential act of war, with the U.S. operating a radar-based early-warning missile detection system to defend against the Soviet Union.

Luckily, a catastrophe never came to pass. The U.S. Air Force had been expanding its space weather analysis capabilities and forecasters managed to intervene, convincing decision-makers that the sun was the likely culprit before any rash commands were issued—but not before bombers were primed to take off.

The Sun
The sun can unleash powerful eruptions that interfere with electronics on Earth, an example of such an eruption came in 1967 when a massive solar storm almost triggered a nuclear war between the U.S. and Russia. Pictured, a photo of the sun taken by the Solar and Heliospheric Observatory in November, 2003. NASA/Getty

A 2016 report regarding the event, published in the journal Space Weather, said that Colonel C. K. Anderson and his solar forecasting staff were credited with providing information that "eventually calmed nerves and allowed aircraft engines to cool as they returned to normal alert stance … it appears that unlike some of the human-error and miscommunication events in the 1970s, bombers did not take to the skies but were nonetheless positioned to do so."

The storm that led to that incident would have been measured as an extreme G5-class storm on the National Oceanic and Atmospheric Administration's geomagnetic storm scale—the most severe type.

The 2016 report said the 1967 storm led to more formal support for current-day space weather forecasting, which now involves satellites peering at the sun, allowing for accurate forecasts of solar flares and other potentially disruptive eruptions. Even so, is a repeat of the 1967 military confusion possible today?

Morris Cohen, an associate professor of electrical and computer engineering at Georgia Tech and the president of the Atmospheric and Space Electricity Section at the American Geophysical Union, told Newsweek he thinks is it "very unlikely" that a solar flare would lead to a misinformed military attack today given developments in space weather technology since then.

"Even back in 1967, when our awareness of space weather was in its infancy, the issue that nearly led to a false attack was not on the science side, it was in the military chain of command and the use of that scientific information," he said.

"We had enough understanding even then to see that a solar flare had occurred, which immediately made for a very different interpretation of that communications outage," Cohen added. "The question was whether the nuclear chain of command were aware of that information, and luckily at the time they were—though perhaps just barely."

The point was echoed by Mathew Owens, professor of space physics in the Department of Meteorology at the University of Reading. He told Newsweek: "Awareness of space weather has increased considerably in the last 50 years. For example, the U.S. Air Force and Naval Research Labs now undertake cutting-edge space weather research themselves. So I'd assume the risk has significantly declined on that front."

However, he added that the 1967 incident "highlights an important thing: the timing and context of a space-weather event is at least as important as the physics."

Cohen identified a few situations in which space weather might "spoof" a military attack. One would be if communications were knocked offline by a solar flare as in 1967. Another would be if a strong solar eruption called a coronal mass ejection (CME) were to knock off power grids. A third could be if signals from GPS satellites were destabilized, which could have effects on financial transactions and cell phone networks.

Although the risks of military confusion caused by a solar flare may have decreased over the decades, solar activity is not harmless. "One of the overarching concerns is with the broad reliance on radio signals across the spectrum," Delores Knipp, research professor and fellow at the American Meteorological Society and co-author of a 2016 report into the 1967 event, told Newsweek.

"The sun has proven very capable of sending blasts of radio interference. In 2006 there was a radio burst that overwhelmed almost all sunlit GPS receivers for tens of minutes. Lots of effort has gone into mitigating that problem."

"Perhaps a larger concern now are efforts to deny radio access and masquerade that interference as a solar event," she added.