Category 1
A spinning motion
Rotation
The daily rise and fall of sea level
Tide
Imaginary line that divides the Earth into the northern and southern hemispheres
Equator
The path an object follows as it moves around another object
Orbit
The motion of one object around another object
Revolution
The line on which an object rotates
Rotation Axis
The lit part of the Moon or a planet that can be seen from Earth
Phase
The part of the lunar cycle in which less of the Moon's near side is lit each night
Waning Phase
The part of the lunar cycle in which more of the Moon's near side is lit each night
Waxing Phase
A day when Earth's rotation axis is leaning along Earth's orbit, neither toward nor away from the Sun
Equinox
A day when Earth's rotation axis is the most toward or away from the Sun
Solstice
The large, dark, flat areas on the Moon
Maria
When the Moon moves into Earth's shadow
Lunar Eclipse
The lighter part of a shadow where light is partially blocked
Penumbra
When the Moon's shadow appears on Earth's surface
Solar Eclipse
The central darker part of a shadow where light is totally blocked
Umbra