First spotted near the end of World War II, their name may have come from the comic strip Smoky Stover.  At first, pilots thought it was a new German secret weapon. Later, explanations ranging from St. Elmo's fire to ball lightning to stress-induced hallucinations were invoked, but many people believed they were [*]  UFOs. For 10 points—name these 
First spotted near the end of World War II, their name may have come from the comic strip Smoky Stover.  At first, pilots thought it was a new German secret weapon. Later, explanations ranging from St. Elmo's fire to ball lightning to stress-induced hallucinations were invoked, but many people believed they were [*]  UFOs. For 10 points—name these small lights spotted by World War II pilots that share a name with a band fronted by Dave Grohl.
First spotted near the end of World War II, their name may have come from the comic strip Smoky Stover.  
Foo Fighters [prompt on “UFO” before “Smoky Stover”]