The famous Lubbock Lights seen over Texas in 1951 were thought to
be flocks of birds flying in V-shaped formations with their undersides
illuminated by mercury-vapor lamps from the city below.

See how much of a problem bad lighting and light pollution are? They
even generated UFO sightings!

Remember those similarly shaped lights that were seen and video taped
over Phoenix in 1997? Turned out to be hoax created by a group of
pilots flying Cessnas in a V formation using only some of their running
lights. An amateur astronomer using his Celestron telescope discovered
this and even told the press, but they basically ignored him. Read this
in Sky & Telescope magazine, but I cannot remember the exact issue.

And thus another UFO legend was born that will never really die.