The Sun Nearly Caused Nuclear War in 1967 Solar flares made it seem like the USSR was jamming US radars By Michael Harthorne, Newser Staff Posted Aug 11, 2016 4:18 PM CDT 21 comments Comments A flare erupts from the sun in 2012. (AP Photo/NASA/SDO/AIA) (Newser) – The sun was nearly responsible for the Cold War going nuclear 50 years ago, according to a study released this week. On May 23, 1967, three US Ballistic Missile Early Warning System radar sites seemed to be jammed. CBS News reports it appeared to the US Air Force, which was now unable to tell if missiles were headed toward the US, that the Soviet Union was responsible. It was considered an act of war, and the Air Force prepared to launch additional planes carrying nuclear weapons. It's unclear how close the US actually came to starting a nuclear war that day, but study author Delores Knipp says, "What we do know is that the aircraft did not launch." That's thanks to a handful of space weather forecasters working at NORAD, who quickly explained to the Air Force that the jamming was actually the result of a massive solar storm. Knipp tells Space it's fortunate the US "invested very early on in solar and geomagnetic storm observations." The 1967 solar storm was one of the biggest of the last century. The solar flare was visible to the naked eye, and the coronal mass ejection that followed affected radio communications for days and made the northern lights visible as far south as New Mexico. As a result of the events of May 23, 1967, both the US and Soviet Union expanded funding for solar weather observation.