A look at our nearest

neighbor in Space!

The Moon

Free powerpoints at http://www.worldofteaching.com

What is the Moon?

• A natural satellite

• The only satellite of the planet

Earth

• about ¼ the size of Earth

Location, location, location!

• About 384,000 km

(240,000 miles)

from Earth

Birth of the Moon

• “Born” 4-5 billion years ago

• Formed most likely from impact of Mars-sized object on Earth

Movements of the Moon

• Revolution – Moon orbits

the Earth every 27-1/3

days

• The moon rises in the east

and sets in the west

• The moon rises and sets

50 minutes later each day

• Rotation – Moon turns on

its axis every 27-1/3 days

• Same side of Moon

always faces Earth

Apogee – when the moon is farthest from Earth

Perigee – when moon is closest to Earth

It’s Just a Phase

• Moonlight is reflected

sunlight

• Half the moon’s surface is

always reflecting light

• From Earth we see

different amounts of the

Moon’s lit surface

• The amount seen is called

a “phase”

FULL

QUARTER

CRESCENT

GIBBOUS

FOUR MAIN SHAPES

Waxing and Waning

• New moon

• Waxing Crescent moon

• First Quarter moon

• Waxing Gibbous moon

• Full moon

• Waning Gibbous moon

• Third Quarter moon

• Waning Crescent moon

• New moon

earth

moon orbit̀ s

earth

last (third)quarter

gibbous moon

full moon

gibbous moon

first quarter

crescent

new moon

crescent

waning Moon

waxing Moon

SUN

Umbra – Total shadow

cast by an object.

Penumbra – partial

shadow cast by an

object.

Lunar Eclipses

• Moon moves into

Earth’s umbra – this

shadow darkens the

Moon completely

• Can only occur at full

moon phase.

About 2-3 per year

• Last up to 4 hours but

total eclipse only lasts

minutes.

Solar Eclipses

• Tip of Moon’s umbra falls on Earth creating shadow on part of the earth.

• Can only occur at new moon phase.

Total eclipses from one location are rare – only once every 360 years! But they happen all the time!

Solar Eclipses.m4v

Earth

Moon

Moon Plane of earth’s orbit

Plane of lunar orbit

Why don’t we see eclipses all the time?

Tides The daily rise and fall of the ocean surface due to

the gravitational pull of the moon and sun.

Gravity of the Moon

• Gravity is stronger when objects are closer together.

• The moon pulls the water on the side of Earth nearest to it more than it pulls the Earth itself. This causes a bulge in the ocean on the side of Earth nearest the moon. This bulge is called the direct high tide.

• Indirect high tide is the bulge in the ocean on the side of Earth that is opposite the moon caused by Earth being pulled away from the water.

High Tide

When the tide reaches its highest point on the shore.

Low Tide When the tide reaches its lowest point on the shore. Low tides occur when water is

pulled away from the areas that lie between the two high tides.

When does High Tide occur?

The moon rises 50 minutes later each day (lunar month is 27 1/3 days)

and so do the tides.

Direct and indirect high tide create 2 high tides and 2 low tides every 24

hrs. 50 min.

Tidal Range The vertical difference between the water level at

high and low tide.

Ex. Bay of Fundy

High tide = 61ft

Low tide = 7 ft 6 in

Tidal range = ?

Gravity of the Sun

The sun is farther away from Earth so the pull is not as strong as the moon’s.

Spring Tides - when Earth, sun and moon line up together.

High tides will be higher and low tides lower. Happens 2 times per lunar month.

Neap Tides - when sun, Earth and moon are at

a right angle.

High tides are lower and low tides are higher.

Happens 2 times per lunar month.

Name this phase!

Full Moon

What time does this phase rise and set?

Name this phase!

First Quarter

Name this phase!

Waxing Crescent

Name this phase!

Waning

Gibbous

Name this

phase!

Third Quarter

From what direction does

the moon rise?

The East

Name this phase!

Waxing Gibbous

Name this phase!

Waning Crescent

What might be happening in this image?

Lunar Eclipse

Name this phase!

Look closely!

Waxing Gibbous

Name this phase!

Full Moon

Name this phase!

New Moon

Does the moon rise or set in the west?

It sets in the west.

Name this phase!

Waning Gibbous

Name this

phase!

Waning Crescent

Name this phase!

Waning Gibbous