By 6:30 A.M. EDT, Io is just about to move off the western limb and Callisto is passing south of the planet's central meridian. If you're more of an evening observer, the waxing gibbous Moon ...

Sixty-seven orbits of Jupiter. Two close-ups of its moon Europa—where astrobiologists think microbial life may exist—21 flybys of far-out Callisto, and nine months in orbit around the biggest ...

Callisto seems the most challenging to write ... The ancient, unchanging moon gets a more archaic sound that evokes an older world. “I’m not a subtle composer,” said Dexter.