By Scott A. Grant, J.D.

Anyone who has ever flown to the west coast and then back knows that the trip home is shorter than the trip out. That is because of the jet stream. The jet stream is caused by the Earth’s rotation and blows fairly consistently from west to east at a height of four to eight miles. The “river of air” can push an object, like a balloon, at speeds from 100 to 275 miles per hour.

The Chinese government recently took advantage of this to launch a spy balloon that passed over the United States from west to east riding the jet stream. Because the Chinese balloon flew at extremely high altitude, it traveled somewhat more slowly than a balloon would at lower altitude. This was not the first time that a foreign power has used the slower moving, high altitude jet stream, against the United States.

In 1944 and 1945, the Japanese launched 9300 “weather balloons,” each carrying an explosive charge. The concept was developed at the Noborito Laboratory, also known as the Imperial Japanese Army’s Number 9 Research Lab. They called the bombs Fu-Go. Japanese scientists discovered the jet stream in 1927 and they attempted to use that knowledge against an enemy.

The Fu-Go were modified weather balloons fitted with incendiary and anti-personnel weapons. The idea was that they would float across the Pacific and then crash in the Pacific Northwest when they ran out of fuel to stay aloft. The Japanese hoped they would start fires, kill, and spread terror. Most of the bombs crashed harmlessly in the Pacific Ocean. 

The trip across the ocean took three days, a distance of almost 5,000 miles. Only about 300 made it all the way. Those that did were the first intercontinental weapons used during warfare. A few exploded in Montana. One landed in Mexico. Some fell on Oregon and Washington, but did not start fires because the forests were too wet. 

The US government knew about the weapons, but decided to keep that information a secret to avoid panicking the public. In May 1945, a group of Sunday School children stumbled upon a balloon bomb while on a picnic near Bly, Oregon. When they investigated their discovery, it exploded. Five children and the pregnant wife of the minister were all killed instantly. They were the first and only victims of the Japanese terror weapon.

Scott A. Grant is a local historian and author. He writes about things he finds interesting and welcomes your comments at

  • Support Community Journalism in Ponta Vedra NewsLine
  • Havana Printing 904-447-5021