Flammarion, (Nicolas) Camille (1842-1925), a French astronomer. He was the author of many popular books on astronomy, including The Atmosphere (1871), Popular Astronomy (1879), and Astronomy for Amateurs (1904). Flammarion contributed to the study of multiple stars and made careful observations of the solar system. He believed that Mars was inhabited and that there was vegetation on the moon. He also made many balloon ascents, studying the upper regions of the atmosphere.

From 1858 to 1862 Flammarion studied at the Paris Observatory. In 1882 he established a private astronomical observatory. He founded the French Astronomical Society in 1887. Flammarion became a spiritualist in his later years and wrote books about life after death.