Jean-Philippe de Chéseaux was a Swiss astronomer and mathematician born in 1718. He is best known for his work in observational astronomy and for his contributions to the understanding of comets. Chéseaux was particularly interested in the study of the comet known as Halley's Comet, which he observed during its return in 1759. In addition to his astronomical studies, Chéseaux was also involved in the development of scientific instruments. He designed and built several telescopes, which improved the accuracy of celestial observations. His work laid the groundwork for future astronomers and contributed to the advancement of the field during the 18th century.