Pons, Jean-Louis (1761–1831)

French astronomer who discovered 37 comets. He was the first to recognize the return of Encke's Comet.

Pons was born in Peyre, near Dauphine. At the age of 28 he became a porter and doorkeeper at the Marseille Observatory. Noting his interest in astronomy, the directors of the observatory gave him instruction, and he turned out to be good at practical observation. Pons was made assistant astronomer 1813 and assistant director 1818. In 1819 he became director of a new observatory at Lucca, northern Italy, moving to the Florence Observatory 1822.

In 1818 Pons discovered three small, tailless comets, among which was one that he claimed had first been seen in 1805 by Johann Encke of the Berlin Observatory. Alerted to this possibility, Encke carried out further observations and calculations, and finally ascribed to it a period of 1,208 days – which meant that it would return in 1822. Its return was duly observed, in Australia, only the second instance ever of the known return of an identified comet. Encke wanted the comet to be named after Pons, but it continued to be called after its discoverer.