Residents of Russia's capital city were astonished last Wednesday when they witnessed a startlingly strange formation hovering high in the sky. Looking something like an enormous interstellar portal, the bright-white circle reminded many of Moscow's citizens of a scene from the movie Independence Day.
Video of the phenomenon has since hit the Internet and has millions bandying explanations, which naturally cover such topics as aliens, UFOs and the impending 2012 apocalypse.
In reality, the abnormality is probably just a rare meteorological curiosity known as a "hole punch cloud" or "fallstreak hole." Nevertheless, the enormous object is eerily reminiscent of Arizona's unexplained Ring of Mystery, which appeared above Flagstaff in 1963.