Nicolas Camille Flammarion, Commandeur-Légion d'honneur (26 February 1842—3 June 1925) was a French astronomer and author. He was a prolific author of more than fifty titles, including popular science works about astronomy, several notable early science fiction novels, and several works about Spiritism and related topics. At the age of nineteen, he published his first work, La Pluralité des Mondes Habités, which caught the public taste and was at once translated into several languages.

Sir George Howard Darwin KCB FRS (9 July 1845 – 7 December 1912) was an English astronomer and mathematician.

Mathematician and astronomer Robert Stawell Ball (1840-1913) was one of the most successful popularizers of science of his time. Tutor to the children of the fourth Earl of Rosse and observer at Birr Castle, he later moved to Dublin as Royal Astronomer of Ireland until becoming Lowndean professor at Cambridge in 1893.  He was named an Honorary Member of the Astronomical and Physical Society of Toronto on 1894-01-09. The asteroid (4809) Robertball is dedicated to him.