The drip effect perhaps?
Not much for me to say on the article as its all been said before.
Taken from the National geographic channel
SourceThe long, documented history of sightings. UFOs were around, in fact, long before humans themselves took to the air. The first account of a UFO sighting in America was back in 1639, when Massachusetts colony governor John Winthrop noted in his journal that one James Everell, “a sober, discreet man,” and two other witnesses watched a luminous object fly up and down the Muddy River near Charlestown for two to three hours. There are documented sightings of sightings of what were then called “airships” during the 1800s as well, such as the July 1884 sighting of a Saturn-shaped UFO (a ball surrounded by a ring) in Norwood, NY, and a fast-moving object that briefly hovered over the startled townspeople of Everest, KS in 1897.