American astronomer Edward Emerson Barnard discovered Amalthea on September 8, 1892, using the 36-inch refractor at Lick Observatory in California. It was the last planetary satellite discovered by eye. From personal experience, I know that seeing it takes a combination of a large telescope (at least 24 inches in aperture), high magnification (above 250x), great sky conditions, and the tiny moon lying at its farthest point from Jupiter from our point of view.
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