When was the planet Neptune discoverd?

Answer 1

Discovered on September 23, 1846, Neptune is notable for being the first planet discovered based on mathematical prediction rather than regular observations.Perturbations in the orbit of Uranus led astronomers to deduce Neptune's existence. It has been visited by only one spacecraft, Voyager 2, which flew by the planet on August 25, 1989.

Answer 2

Neptune is the outermost planet of the gas giants. It has an equatorial diameter of 49,500 kilometers (30,760 miles). If Neptune were hollow, it could contain nearly 60 Earths. Neptune orbits the Sun every 165 years. It has eight moons, six of which were found by Voyager. A day on Neptune is 16 hours and 6.7 minutes. Neptune was discovered on September 23, 1846 by Johann Gottfried Galle, of the Berlin Observatory, and Louis d'Arrest, an astronomy student, through mathematical predictions made by Urbain Jean Joseph Le Verrier.

Answer 3

Neptune was discovered by astronomers who were also mathematicians and that they used their math skills to find it. Many astronomers had seen Neptune, but didn't realize they were looking at a planet. Galileo was one of the astronomers who observed Neptune, but thought it was a star. Planets look like disks through telescopes; stars look like points of light. Galileo's telescope was not powerful enough to reveal that the object he saw was a disk.

It was not until the discovery of the planet Uranus by William Hershel in 1781, that astronomers realized there might be another planet beyond its orbit. Uranus' orbit was a bit strange. Astronomers thought, but couldn't prove, that it was caused by the gravitational pull of another planet. A young British astronomer and mathematician , John C. Adams, decided to calculate the location of the mystery planet. In 1843, he set to work on it. According to his calculations, Neptune was about 1 billion miles or 1.6 billion kilometers farther from the Sun than Uranus. In 1845, he had determined the location of Neptune and sent the results to Sir George B. Airy, the astronomer royal of England. Airy took no action with Adams' work.

Answer 4

"Neptune was first observed by Galle and d'Arrest on 1846 Sept 23 very near to the locations independently predicted by Adams and Le Verrier from calculations based on the observed positions of Jupiter, Saturn and Uranus. "

http://www.nineplanets.org/neptune.html