How are Comets Relevant to History?
In the eyes of everyone in about 300 years ago, comets were bad news. The first references to comets appear in Chinese annals from the 11th century BC. Right away, comets are regarded as heavenly signs, for good or bad. For example, in Mexico, the Aztec ruler Moctezuma believed that the arrival of the Spaniards was a fulfillment of prophecies brought by comets. He then felt that the heavens had turned against him. In 1066, Harold, the ruler of Saxon England, learns that his kingdom has been invaded by William of Normandy. Many people thought that the comet was a bad omen. However, after Harold was killed in the Battle of Hastings, William claimed that the comet had forecast his success. It was until 1577, when the Danish astronomer Tycho Brahe proved that comets were actually celestial bodies, comets were no longer regarded as omens from the heaven. In the 17th century, Sir Isaac Newton showed that the movements of comets referred to the same laws that control the planets in their orbi
