Related Clues:
- Astronomer's sightings
- Ganymede and Lysithea, to Jupiter
- Saturn has many
- Landers' counterparts
- Phoebe and Rhea, to Saturn
- Time periods lasting about 29 1/2 days
- Shows a seat?
- Satellites, e.g.
- Mercury's lack
- Jupiter has 63
- Hindsights?
- Planetary orbiters
- Mars pair
- Io and Ganymede, e.g
- Crescent and half