Meanwhile, Le Verrier by letter urged Berlin Observatory astronomer Johann Gottfried Galle to search with the observatory's refractor. Heinrich d'Arrest, a student at the observatory, suggested to Galle that they could compare a recently drawn chart of the sky in the region of Le Verrier's predicted location with the current sky to seek the displacement characteristic of a planet, as opposed to a fixed star. On the evening of 23 September 1846, the day Galle received the letter, he discovered Neptune within 1° of where Le Verrier had predicted it to be, about 12° from Adams' prediction. Challis later realised that he had observed the planet twice, on 4 and 12 August, but did not recognise it as a planet because he lacked an up-to-date star map and was distracted by his concurrent work on comet observations.
Meanwhile , Le Verrier by letter urged Berlin Observatory astronomer Johann Gottfried Galle to search with the observatory 's refractor . Heinrich d'Arrest , a student at the observatory , suggested to Galle that they could compare a recently drawn chart of the sky in the region of Le Verrier 's predicted location with the current sky to seek the displacement characteristic of a planet , as opposed to a fixed star . On the evening of 23 September 1846 , the day Galle received the letter , he discovered Neptune within 1 ° of where Le Verrier had predicted it to be , about 12 ° from Adams ' prediction . Challis later realised that he had observed the planet twice , on 4 and 12 August , but did not recognise it as a planet because he lacked an up - to - date star map and was distracted by his concurrent work on comet observations .
What did Henrich d'Arrest seek to find?
What did Henrich d'Arrest seek to find ?
the displacement characteristic of a planet
the displacement characteristic of a planet