He became the assistant of his father, William Cranch Bond, and in 1859 succeeded him as director of the Harvard College Observatory. Much of his work was done in cooperation with his father. While they were studying Saturn together, George, in 1848, discovered its eighth satellite, Hyperion (which was independently discovered in that same year by the English astronomer William Lassell). His observations led him to reject the previously held theory that the rings of Saturn were of solid structure, though his hypothesis of their being in fluid state was in turn soon discarded. His memoir on the Donati comet of 1858 in the Annals of the Harvard College Observatory, Vol. III, remains one of the most complete descriptions of a great comet that has been written. His revision of his father's work on the Orion nebula was published posthumously. His photographs of the moon created a sensation among astronomers in Europe when taken there in 1851. He was a pioneer in the use of photography in mapping the sky, determining stellar parallax, and measuring double stars. He also used photographs for determining the comparative brightness of the planets.