What's odd is that this phenomenon kept repeating every few years only with more advanced craft replacing the earlier ones. By the thirties, people were seeing mysterious planes, ghost fliers as they were called. They flew in all kinds of weather and were seen in areas where airplanes were very rare (mainly in upper Scandinavia). They are never seen taking off or landing (I've read fairly recently articles from Britain of people being scared half out of their wits by a World War II fighter plane that comes in low over them as though it might crash. Where it comes from and where it goes is not known). Then it became ghost rockets in the 1940s that were also seen mostly over Scandinavia. They would fly silently and explode silently—usually.

In one case, a ghost rocket allegedly crashed on July 19, 1946 at Lake Kölmjärv in Sweden. At about a quarter of twelve noon on a very hot summer day, Knut Lindbäck and Beda Persson watched a dull gray object Lindbäck claimed was "two meters long and had a snub nose and a stern that was pointed" fall out of the sky and into the lake throwing up a huge cascade of water. Lindbäck also thought the object also had two small wing-like protrusions on the sides but could not be certain of this. "Everything happened so quickly," he said. Frideborg Tagebo was standing about 600 feet away from the point of impact and was jolted by the terrific explosion. "When the thing struck down," Tagebo said, "it was like a bomb had detonated." Tagebo's dog ran off howling in fright.

The Swedish military dispatched a company of soldiers under the command of Lt. Karl-Gösta Bartoll who arrived the next day and sealed off the area while the crash site was searched for about a fortnight (other sources say three weeks). Bartoll stated that the lake floor bore a very fresh deep gouge not only revealing but forcing up deeper layers of the lakebed. There was no doubt in his mind that a real object had fallen into the lake and exploded. He had two engineers check for radiation but none was detected. And try as they might, no trace of the object was ever recovered either.

The great aviator, James Doolittle and RCA president David Sarnoff even went to Scandinavia supposedly on different missions for different purposes but were later found to have been sent to see just how much evidence there was behind the ghost rocket phenomenon. Eric Malmberg, who headed the Swedish Ghost Rocket Committee, stated four decades later "if the observations are correct, many details suggest it was some kind of a cruise missile that was fired on Sweden. But nobody had that kind of sophisticated technology in 1946." There is a photo of an alleged ghost rocket taken in Sweden in 1946. The photographer caught it by accident and stated it lasted only a brief instant and therefore believed it to be a meteor. The Swedish Defense Staff to this day has no opinion:

ghost rocket?