A year earlier, amateur teenage astronomer Leo Biederman discovered a new comet that is the one now certified to hit within the year.

• 美国一名热衷天文学的中学生里欧（伊莱亚伍德饰演）无意间发现一颗新彗星，没想到这颗巨大的彗星竟朝地球直冲而来，在一年内将撞上地球，人类命运危在旦夕。