Short answers, pulled from the story.
Edward Emerson Barnard discovered the moon Amalthea on the 9th of September 1892 while working at Lick Observatory. This event marked the final time astronomers found a planetary satellite using only eyes and glass lenses.
The moon Amalthea orbits Jupiter at a distance of 181,000 kilometers from the planet's center with an irregular shape measuring approximately 250 by 146 by 128 kilometers. Its orbit tilts 0.37 degrees relative to Jupiter's equator while maintaining an eccentricity of 0.003.
Scientists determined the density of the moon Amalthea as 0.86 grams per cubic centimeter during a Galileo orbiter flyby on the 5th of November 2002. This low value suggests the body consists of porous water ice or a very loose rubble pile containing hydrous minerals.
Pan stands as the largest crater on the moon Amalthea with a diameter of 100 kilometers and a depth of at least 8 kilometers. Another feature named Gaea measures 80 kilometers across and likely reaches twice that depth along with bright spots known as Lyctos Facula and Ida Facula.
Micrometeorite impacts eject dust particles from the surface of the moon Amalthea into space because escape velocity never exceeds 1 meter per second near Jupiter. This debris drifts away easily after collisions to form the Amalthea Gossamer Ring surrounding the planet.