While at Lick Observatory, Barnard was the first astronomer to discover a comet using photgraphic plates. In 1889, he became the first astronomer to observe the eclipse of Saturn's satellite Iapetus.
Barnard moved to California in 1887 to inaugurate the new observatory at Mount Hamilton near San Jose. He discovered the first non-Galilean moon of Jupiter, Amalthea, in September 1892 over 275 years after Galileo's discoveries. Observatory staff…