science · 25 December 1758 · 266 years ago
In 1758, the predicted return of Halley's comet was first sighted by German farmer and amateur astronomer, Johann Georg Palitzsch, as a faint object in Pisces. Edmond Halley had predicted in 1705 the return of the comet to the Earth's vicinity every 75.5 years. For the first time the scientific prediction had been proven. Halley himself had died 16 years before this new event. Palitzsch also observed the 6 Jun 1761 transit of Venus, when he saw a black band linking Venus and the Sun near the beginning and end of the transit ("black drop effect") and correctly interpreted this as evidence that Venus possessed an atmosphere. He also measured the period of the variation of the brightness of the star Algol.
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