Through the ages, people have attributed meaning to unusual celestial apparitions such as comets. Such is the case for perhaps the most famous comet, the one named after British astronomer Edmond Halley, who determined that periodic sightings of a comet were in fact of the same object. Although recorded sightings of Halley’s Comet go back more than 2,000 years, its most famous association is with the Norman invasion of England in 1066, including the first illustration of the comet on the Bayeux Tapestry. Making an appearance roughly every 76 years, during its last close approach in 1986 several nations dispatched spacecraft for a close examination of this celestial visitor to the inner solar system. Other comets have since received close scrutiny, increasing our understanding of these primordial objects. Left: Scene from the 11th century Bayeux Tapestry showing the scene of the Battle of Hastings with a comet in the sky. Right: Close up of the comet from the Bayeux Tapestry. Credit: Im...
