Challis, James

ORDERBY-NAME: Challis, James

OTHER-NAME: None

BIRTH: 12 December 1803, Braintree, Essex, England

DEATH: 3 December 1882, Cambridge, England

CATEGORY: Science

DISCIPLINE: Astronomy

ASSESSMENT: He blew his chance to be the discoverer of Neptune

LANGUAGE: English

EDUCATION: Mill Hill School, London; Trinity College, Cambridge

ACHIEVEMENT: Plumian Professor (1835);  Director of Cambridge Observatory (1836)

MAJOR-WORK: Astronomical Observations Made at the Observatory of Cambridge (1832–64)

PARENTS: John Challis father.

SPOUSE: Widow of his patron Rev. Daniel Copsey, second daughter of Samuel Chandler

SIBLINGS: Three brothers

CHILDREN: One son, one daughter

DETAILS:

Challis entered Trinity College, Cambridge in 1821 and after graduation in 1826 was elected a Fellow.  In 1835 when George Airy* was made Astronomer Royal, Challis succeeded him as Plumian Professor and then Director of the Cambridge Astronomical Observatory. 

It was only Challis’ aimiable character that saved him from ridicule by his peers after he (privately) published his views on his weird theory of everything (a new physical law that connected all phenomena and was supposed to replace Newton’s ideas). 

Challis’ moment of infamy came in 1845.  A year earlier he had been approached by the young astronomer John Couch Adams who was looking for data on the perturbations in the orbit of the planet Uranus.  Adams believed these would reveal the influence on Uranus of a new and as yet unknown planet.  In September 1845 Challis did the math and showed Adams where such a new planet might be found.

The following July Airy was pressing Challis hard for an examination of the night sky to find the planet and even offered to provide Challis with an assistant.  Challis refused the offer.

Between the end of July and mid-August Challis examined the area of sky in question:  on July 29 and (due to moonlight) only again on August 12.  He saw that there had indeed been a shift in position in one ‘star’ (this would have been the moving planet), but set the data aside until he had made much broader sweeps of the sky.

Before he could take another look, on September 23 the Berlin Observatory team found Neptune,  and Challis’ name was mud.

He never lived it down.

ONELINER:  James Challis, the man who missed Neptune

EXTRA-CONNECTIONS:  He kept up correspondence with GG Stokes*

BIBLIOGRAPHY:

DSB

EB