Omens, God’s wrath, or just plain misfortune; comets were seen by our Medieval forebears as a disturbance in the natural state of the heavens, portending disaster, pestilence, or famine, and if you were really unlucky, all three.  Harold, Earl of Wessex and later King, before he did battle against William of Normandy in 1066, must have had some misgivings with Halley’s comet nicely lighting up the northern sky (we now know it was comet Halley); he probably should have kept both eyes on the battle. Portent indeed; the Norman conquest changed irrevocably the history of Britain.

It seems that the ancient Chinese were a little more rational in their deliberations on comets – they referred to them as brush stars, and as early as 613 BC were computing approximate orbits.  In fact it is ancient Chinese astronomy records that have enabled modern astronomers to confirm calculated orbit periodicities for comets like Halley. Continue reading →