7th GradeUnit 7:

Relationships between Earth and Moon

Lesson 2: Motion of the Earth and

MoonVocabulary of Instruction:

Terminator• The line

between the day side and the night side of a planetary body in astronomy.

Eclipse• A chance alignment

between the Sun and two other celestial objects within the solar system in which one body blocks the light of the Sun from the other and casts a shadow on that object.

Penumbra• The shadow cast, in an eclipse, where the

light is partly cut off by the intervening body. It is the largest part of the shadow.

Umbra• Area of the shadow of an eclipse, dark center of

a sunspot. The darkest part of a moon’s shadow.

This photo is centered on Earth's umbral shadow.

Waxing• Part of the

moon that is getting bigger and is becoming illuminated by the sun.

Waning• Diminishing

the size of the moon or slowly getting smaller.

Gibbous• Swelling by a

regular curve or surface; the moon is gibbous between the half-moon and the full moon.

Crescent• Phase of the

moon when it is shaped as a C or as an inverted C, new moon, moon in its last quarter.

Lunar Limb• The edge of

the visible surface of the Moon as viewed from Earth.

Phase•The different shapes of the moon as seen from Earth. There are 8 phases of the moon as described in the next two slides…

Phase 1 - New Moon - The side of the moon that is facing the Earth is not lit up by the sun. At this time the moon is not visible.

Phase 2 - Waxing Crescent - A small part (less than 1/2) of the moon is lit up by the sun at this point. The part that is lit up is slowly getting bigger.

Phase 3 - First Quarter - One half of the moon is lit up by the sun at this point. The part that is lit up is slowly getting bigger.

Phase 4 - Waxing Gibbous - At this time half of the moon is lit up by the sun. The part that is lit is slowly getting bigger. Waxing means to slowly get bigger.

8 Phases of the Moon

Phase 5 - Full Moon - The side of the moon that is lit up by the sun that is facing the Earth. The entire moon is lit up at this point and looks clear.

Phase 6 - Waning Gibbous - The moon is not quite lit up all the way by sun. The part of the moon this is lit is slowly getting smaller. Waning means to slowly get smaller.

Phase 7 - Last Quarter - Half of the moon is lit up by the sun. The part that we can see lit up is slowly getting smaller.

Phase 8 - Waning Crescent - A small part of the moon is lit up by the sun at this point. It is getting smaller by the minute.

8 Phases of the Moon

Lunar Eclipse• Occurs at a full

moon when the Earth is directly aligned between the Moon and the Sun, blocking the sunlight from reaching the Moon.

Solar Eclipse• When then

moon is directly aligned between the Earth and the Sun, blocking the sunlight from reaching the Earth.