Unindented Flying Objects (UFOs)

In the 1940s and 50s reports of "flying saucers" became an American cultural phenomena. Sightings of strange objects in the sky became the raw materials for Hollywood to present visions of potential threats. Posters for films, like Earth vs. the Flying Saucers from 1956 illustrate these fears. Connected to ongoing ideas about life on the Moon, the canals on Mars, and ideas about Martian Civilizations, flying saucers have come to represent the hopes and fears of the modern world. Are these alleged visitors from other worlds peaceful and benevolent or would they attack and destroy humanity?