On January 5, 1943, near Guadalcanal, the cruiser USS Helena fired a new kind of five-inch shell at Japanese aircraft. The result looked impossible to men trained in conventional anti-aircraft warfare ...

When the shell came near an aircraft, this would distort the waves and detonate the shell. Put simply, the shell didn't need to hit the aircraft, just get in the proximity of it. Hence the name, ...

"Mortar shells mark their path through the air with a smoke trail from the lit fuse, helping the government artillery officers to know how to adjust the length of the fuse to ensure maximum damage.