Foo Fighters(English Language)

The term foo fighter was used by Allied aircraft pilots in World War II to describe various UFOs or mysterious aerial phenomena seen in the skies over Europe and the Pacific theater. Contemporary witnesses often assumed that the foo fighters were secret weapons employed by the enemy. Despite these fears, foo fighters (whatever they might have been) were apparently never reported to have harmed or tried to harm anyone. Though usually thought of as blobs of light or fire, several different types of reported phenomena were classed as "foo fighters".
There were several other terms used to describe these objects (such as "Kraut fireballs"), but "foo fighter" seems to have been the most popular.
The term is generally thought to have been borrowed from the often surrealist comic strip Smokey Stover. Smokey, a firefighter, was fond of saying "Where there's foo there's fire." (this "foo" may have come from "feu", the French word for "fire", or from Smokey's pronunciation of the word "fuel".) A Big Little Book titled Smokey Stover the Foo Fighter was published in 1938.
In the same vein, "Foo" could be derived from the French "Fou," or "mad." "Foo fighter" was supposedly used as a semi-derogatory reference to Japanese fighter pilots (known for erratic flying and extreme maneuvering), it became a catch-all term for fast moving, erratically flying objects (such as UFOs).
Some have thought that the term refers to Kung fu ("kong foo") fighting, because of the reported wild, erratic movements of these aerial objects. The term Kung fu was, however, little known in the English language until the late 1960s when it became popular because of the Hong Kong films and the later television series: before that it was referred to primarily as "Chinese Boxing".

History Foo fighters were reported on many occasions from around the world.
A nighttime sighting from September, 1941 in the Indian Ocean was similar to some later Foo Fighter reports. From the deck of the S.S. Pulaski, (a Polish merchant vessel transporting British troops), two sailors reported a "strange globe glowing with greenish light, about half the size of the full moon as it appears to us." (Clark, 230) They alerted a British officer, who watched the object's movements with them for over an hour.
On February 28, 1942, just prior to its participation in the Battle of the Java Sea, the USS Houston reportedly saw a large number of strange, unexplained yellow flares and lights which illuminated the sea for miles around.
A report was made from the Solomon Islands in 1942 by United States Marine Corp Stephen J. Brickner. Following an air raid alarm, Brickner and others witnessed about 150 objects grouped in lines of 10 or 12 objects each. Seeming to "wobble" as they moved, Brickner reported that the objects resembled polished silver and seemed to move a little faster than common Japanese aircraft.
Foo fighter reports were mentioned in the mass media. A 1945 Time story stated "If it was not a hoax or an optical illusion, it was certainly the most puzzling secret weapon that Allied fighters have yet encountered. Last week U.S. night fighter pilots based in France told a strange story of balls of fire which for more than a month have been following their planes at night over Germany.
No one seemed to know what, if anything, the fireballs were supposed to accomplish. Pilots, guessing it was a new psychological weapon, named it the 'foo-fighter' ... Their descriptions of the apparition varied, but they agree that the mysterious flares stuck close to their planes and appeared to follow them at high speed for miles. One pilot said that a foo-fighter, appearing as red balls off his wing tips, stuck with him until he dove at 360 miles an hour [580 km/h]; then the balls zoomed up into the sky."
The Robertson Panel cited foo fighter reports, noting that their behavior did not appear to be threatening. Interestingly, the Robertson Panel's report noted that many Foo Fighters were described as metallic and disc shaped, and suggested that "If the term "flying saucers" had been popular in 1943-1945, these objects would have been so labeled."
Explanations and Theories

• The phenomenon could be based on the misinterpretation of the Luftwaffe's standard operating procedure of having selected anti-aircraft batteries near German airfields fire colored flare patterns in regular intervals to aid Luftwaffe night fighters with visual navigation.
• Proponents of the extraterrestrial hypothesis (commonly shortened to ETH) have suggested that foo fighters are evidence of extraterrestrials visiting Earth.
• It has also been suggested that the foo fighter was a secret disk-shaped Luftwaffe aircraft nicknamed the "feuerfighter" by the Germans, but as this hypothetical name is a mix of German and English, and as no such craft has been found, this explanation is likely an urban legend.
• Likewise, the suggestion that some sightings of foo fighters may have been night-sightings of the German Messerschmitt Me 163 Komet rocket-plane makes no sense: the Me 163 was completely unsuitable for nocturnal operations since it had only a few minutes of fuel, totally insufficient to make contact with an enemy at night, carried no airborne interception radar, and lacked all night-flying equipment which would have been vital to make its characteristic engine-out glider-style deadstick landing at night.
• A type of electrical discharge from airplanes' wings has been suggested as an explanation.
• Another theory suggests that pilots may have seen ball lightning.
• Reports of strange lights in the night are common throughout history, with explanations ranging from elves and Wild Hunt to UFO. It seems to be another example of the common, although still not fully explained, phenomenon.
• In the X-Files episode 3.16 "Apocrypha", The Well Manicured Man answers Agent Mulder's question as to what was salvaged off the bottom of the Pacific ocean, "It was a UFO, a so-called foo fighter downed by American fighter pilots in the second World War."