... Neptune's Moon Proteus . ... Jupiter's Moon Amalthea . ... Amalthea is Jupiter's fifth largest moon, much smaller than the four Galilean satellites Io, Europa, Ganymede, and Callisto. ... The unusual geometry of this stellar nebula creates somewhat of a mystery. At the nebula's center is a young binary star system that probably created the nebula, but how? ... Comet Hale-Bopp Update . ... It is an emission nebula surrounding a cluster of hot, young stars called the 30 Doradus super cluster. ...