Ghost rockets

Ghost rockets or Scandinavian ghost rockets (Swedish: spökraketer; Norwegian: spøkelsesraketter; Finnish: aaveraketit) are a series of observations of unidentified flying objects over Finland, Sweden, and Norway in 1946.

Generally considered at the time to have been Soviet test rockets or missiles, the opening of Soviet records reveals that was unlikely, so, the conspiracy-inclined assumed it had to be alien craft.