Case file · Cosmic event
Halley's Comet in the Nihon Shoki
In the 13th year of Emperor Tenmu (684) the court chroniclers noted a 'broom star' in the northwest, the first Japanese record of Halley's Comet.
684 CE · 34.47, 135.82 · status: official
The account
Comets were read as omens of rebellion or death in East Asian court astronomy, so they were logged carefully. The 684 entry matches the comet's known return and is the first of many Japanese observations.