Halley's Comet in May 1910. The April 1910 approach of Halley's Comet was the first for which photographs exist. The approach was relatively close, and on 18 May the Earth passed through the tail of the comet. Despite astronomers stating that the cometary tail was so diffuse that there would be no noticeable effect, the media published sensational and incorrect predictions of global cyanide poisoning. Halley's Comet is the only naked-eye comet certain to return within a human lifetime (every 75 years or so). It derives its name from Edmond Halley, an eighteenth-century astronomer who computed its orbit. The comet has been observed since at least 240 BC.