| A | B |
|---|
| Celestial object | any object in space |
| Geocentric | model of the solar system in which all celestial bodies revolve around the Earth |
| Heliocentric | model of the solar system in which all celestial objects revolve around the sun |
| Revolution | movement of one object around another in space |
| Rotation | spinning of an object on an imaginary axis |
| Lunar eclipse | occurs only during a full Moon when Earth passes between sun and moon (Earth’s shadow falls on the moon) |
| Solar eclipse | occurs during a new Moon when the moon passes between sun and Earth (Moon’s shadow falls on the Earth) |
| Phase | daily changes in the moons appearance |
