Disaster Planning for Cosmic Impacts: Progress and Weaknesses

On the evening of June 18, 1178, several witnesses near Canterbury, England saw a spectacular night sky event (Ingram 1999). These observers reported directly to a monk who was keeping detailed records of events occurring in or around Christ Church Cathedral. Fortunately, this diary, the Chronicles of Gervase has survived and provides a detailed description of the strange events of 1178: This year, on the Sunday before the Birth of Saint John the Baptist, after sunset when the moon had first become visible, a marvellous phenomenon appeared to five or more men while sitting facing it. Now there was a bright new moon, and as usual the horns protruded to the east; and lo, suddenly, the upper horn split in two. From the middle of this division a firebrand burst forth, throwing over a considerable distance fire, hot coals and sparks. Meanwhile the body of the moon which was lower [than this] writhed as if troubled, and in the words of those who told this to me and who saw it with their own eyes, the moon throbbed as a beaten snake. It then returned to its former state. This phenomenon was repeated twelve times and more, the flame assuming various twisting shapes at random then returning to normal. And after these vibrations it became semi-dark from horn to horn, that is, throughout its length. Those men who saw this with their own eyes reported these things to me who writes them; [they are] prepared to give their word or oath that they have added nothing false to the above.