[1] Bessel was born in Minden, Westphalia, then capital of the Prussian administrative region Minden-Ravensberg, as second son of a civil servant into a large family.

Bessel came to the attention of Heinrich Wilhelm Olbers, a practising physician of Bremen and well-known astronomer, by producing a refinement on the orbital calculations for Halley's Comet in 1804, using old observation data taken from Thomas Harriot and Nathaniel Torporley in 1607.

Having finished his commercial education, Bessel left Kulenkamp in 1806 and became assistant at Johann Hieronymus Schröter's private observatory in Lilienthal near Bremen as successor of Karl Ludwig Harding.

[2] Despite lacking any higher education, especially at university, Bessel was appointed director of the newly founded Königsberg Observatory by King Frederick William III of Prussia in January 1810, at the age of 25, and remained in that position until his death.

[3] In 1842 Bessel took part in the annual meeting of the British Association for the Advancement of Science in Manchester, accompanied by the geophysicist Georg Adolf Erman and the mathematician Carl Gustav Jacob Jacobi, where he gave a report on astronomical clocks.

Neumann introduced Bessel's exacting methods of measurement and data reduction into his mathematico-physical seminar, which he co-directed with Carl Gustav Jacob Jacobi at Königsberg.

Thanks to these results astronomers had not only enlarged the vision of the universe well beyond the cosmic magnitude, but after the discovery in 1728 by James Bradley of the aberration of light a second empirical evidence of the Earth's relative movement was produced.

[11] A short time later Friedrich Georg Wilhelm Struve and Thomas Henderson reported the parallaxes of Vega and Alpha Centauri.

Precise measurements with a new meridian circle from Adolf Repsold allowed Bessel to notice deviations in the motions of Sirius and Procyon, which must be caused by the gravitational attraction of unseen companions.

One unpublished new chart enabled Johann Gottfried Galle to find Neptune near the position calculated by Le Verrier in September 1846 at Berlin Observatory.

Like numerous astronomers of his time Bessel dealt on the field of geodesy, too,[16] first theoretically, when he published a method for solving the main geodetic problem.

Xyletinus besseli[33] a fossil beetle from the Eocene belonging to the family Ptinidae, found in the Baltic amber in Sambia, was named in his honour.