Caption:
A Babylonian tablet recording the appearance of Halley's comet around the 22 to the 28 of September, 164 BC. Babylonian astronomers recorded daily astronomical observations from at least the 7th century BC. Halley's Comet is the best known of the short-period comets and is visible from Earth every 75-76 years. It is the only short-period comet that is clearly visible to the naked eye from Earth. It was observed and recorded by astronomers since at least 240 BC. The comet's periodicity was first determined in 1705 by English astronomer Edmond Halley, after whom it is now named.