UFO一个被称为"不明飞行物"的词，最早出现于50年代西方的报刊上。本书收集了多年来有关UFO的一些传说，很多可见于当时的报刊上，如"空中奇遇"、"神秘的失踪"、"天外来客"等。无声无息，神出鬼没的UFO吸引了全世界所有人的目光。虽然一些有关UFO之谜逐步被人类解开，但仍有许多的有待进一步的考察和研究。
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