Who discovered Jupiter's moon Himalia in 1904?

Charles Dillon Perrine discovered Jupiter’s moon Himalia in 1904. He found it on 3 December while examining photographic plates made at Lick Observatory in California.

Perrine used the observatory’s 36-inch Crossley reflecting telescope, which he had recently rebuilt. Himalia appeared as a faint object moving against the background stars. Additional photographs were needed to establish that it was orbiting Jupiter rather than being a distant asteroid. The discovery was announced as Jupiter’s sixth satellite; the moon was not given the name Himalia until decades later.

Himalia is the largest member of the Himalia group, a family of irregular, prograde Jovian satellites. Their similar orbits and appearances suggest that they may be fragments of a captured asteroid that was broken apart by a collision. Himalia itself is dark, with a very low reflectivity, and has a mean radius of roughly 85 kilometers.

The main historical confusion is among Jupiter’s early satellite discoverers. Philibert Melotte discovered Pasiphae in 1908, while Seth Barnes Nicholson discovered several later moons. Perrine also discovered Elara in 1905, making him responsible for two of Jupiter’s outer moons.