Eminent Cornell astronomer and bestselling author Sagan debunks the paranormal and the unexplained in a study that will reassure hardcore skeptics but may leave others unsatisfied. To him, purported UFO encounters and alien abductions are products of gullibility, hallucination, misidentification, hoax and therapists' pressure; some alleged encounters, he suggests, may screen memories of sexual abuse. He labels as hoaxes the crop circles, complex pictograms that appear in southern England's wheat and barley fields, and he dismisses as a natural formation the Sphinx-like humanoid face incised on a mesa on Mars, first photographed by a Viking orbiter spacecraft in 1976 and considered by some scientists to be the engineered artifact of an alien civilization. In a passionate plea for scientific literacy, Sagan deftly debunks the myth of Atlantis, Filipino psychic surgeons and mediums such as J.Z. Knight, who claims to be in touch with a 35,000-year-old entity called Ramtha. He also brands as superstition ghosts, angels, fairies, demons, astrology, Bigfoot, the Loch Ness monster and religious apparitions. ~ Publishers Weekly