Adams, John Couch (1819-1892)

English astronomer. He mathematically deduced the existence of the planet Neptune in 1845 from the effects of its gravitational pull on the motion of Uranus, although it was not found until 1846 by J G Galle. Adams also studied the Moon's motion, the Leonid meteors, and terrestrial magnetism.

Adams was born in Landeast, Cornwall, and educated at Cambridge, where he spent virtually his entire career. He became professor of mathematics at the University of St Andrews, Fife in 1858, was Lowndean professor of astronomy and geometry at Cambridge 1859-92, and director of Cambridge observatory 1861-92.

The calculations to account for certain aberrations in the orbit of Uranus were taken up independently by Adams and the French astronomer Urbain Leverrier.

By 1845 Adams had determined the position and certain characteristics of the hypothetical planet affecting the orbit, but a search for the new planet was not instigated for nearly a year at Cambridge. Meanwhile, Leverrier sent his figures to Galle at the Berlin Observatory, and Galle, having better maps, was able to find the planet within a few hours. The discovery of Neptune was credited to Leverrier.