Sept. 9, 1892: Edward Emerson Barnard sees Amalthea

Today in the history of astronomy, a moon of Jupiter is discovered.
By | Published: September 9, 2025

Gemini Sparkle

Key Takeaways:

  • E.E. Barnard discovered Jupiter's fifth moon, Amalthea, on September 9, 1892, using the 36-inch refractor at Lick Observatory.
  • This discovery marked the first detection of a Jovian moon in 280 years, following Galileo's 1610 discovery of Io, Europa, Ganymede, and Callisto.
  • Amalthea's orbit is closer to Jupiter than the Galilean moons.
  • While Camille Flammarion suggested the name Amalthea, its widespread adoption occurred after Voyager 1's imagery in 1979.

When Edward Emerson Barnard peered through the 36-inch refractor at Lick Observatory on Sept. 9, 1892, and spotted Amalthea, it marked the first discovery of a moon of Jupiter in 280 years. Galileo had discovered the four largest jovian moons – Io, Europa, Ganymede, and Callisto – in 1610. Though this fifth moon was closer to Jupiter than any of the Galilean moons, Barnard was known for his exceptional vision and observational skills. French astronomer Camille Flammarion suggested the name Amalthea for the moon, after the nymph who cared for the infant Zeus (Jupiter in Roman mythology), but the name wasn’t widely adopted until after Voyager 1 imaged Amalthea in 1979.