Ancient cultures often turned to myth and legend to explain comets, viewing them as cosmic messengers of death and pestilence. These characterizations are known as apophenia, the perception of connections and meaningfulness in unrelated phenomena. In ancient Thailand, indigenous beliefs from animism and superstition predated those from outside influences of Buddhism, Hinduism, and Islam. A Thai scroll in the British Library entitled Tamra Phichai Songkhram, meaning a divination manual, contains accurate illustrations of comets with positional information. As with the beliefs of many other cultures, the document portends calamities, assassinations, monetary rewards, and military operations, defeats, and victories associated with comets. The scroll dates from 1800 to 1880, including the reigns of the Siam kings, Rama IV and his son, Rama V. In contrast, modern ideas of astronomy, including comets, came to Thailand during the 19th century as it was opened to western culture by King Rama IV. Rama IV, the father of Thai science, and Rama V gained astronomical knowledge using traditional Siam texts based on Indian sources and studied English texts as well. Several prominent comets were recorded by Rama IV and Rama V. During their lifetimes, they witnessed the Great Comet of 1811 (C/1811 F1 Flaugergues) and Comet Donati (C/1858 L1), among others. The mixture of modern and ancient perceptions of comets occurred during the 19th century as Thailand transitioned from old beliefs to new scientific thought.
This work was partially supported by NSF Planetary Astronomy Program Grant No. 0908529.