Dexter defines The Galilean Suite as tone poems, but while Holst’s inspiration for The Planets was astrological, this work is influenced by what we know about the moons’ geology.

Io, a highly volcanic world, is the innermost Galilean moon of Jupiter. Got a pair of binoculars? Point them at Jupiter tonight—or any night during its bright opposition month—and you’ll ...

All together, they form a satellite system which is called the Jovian system. The most massive of the moons are the four Galilean moons: Io; Europa; Ganymede; and Callisto, which were independently ...