Earth’s Moon- Our Unique Celestial Neighbor

Definition: a moon is a natural satellite that revolves around a planet

Play Guster Satellitefrom desktop

Origin of Earth’s Moon Collision between proto-Earth and a Mars-

size object. This is known as a Catastrophic Event

The Moon’s OriginOrpheus Theory

Borne from a planetary collision between proto-Earth and Orpheus (another planetary object initially between Earth and Mars).

Age of Earth’s Moon Approximately 4 billion years old (b.y.o) Evidence- Chemical analysis and radioactive

dating of Moon rock collected during Apollo Missions in the 1970’s

Earth’s Moon Distance: is our closest neighbor in space

at an average distance of 238,857 miles

Physical Characteristics Equatorial Diameter is about one-quarter

the size of Earth. This is large compared to “mother planet”- Unique

Gravity Comparison

One- sixth less gravity then Earth because the moon has less mass

Walking on the Moon

Temperatures 240°F in the Sun - 240°F in the shade Because there’s no atmosphere to transfer

heat

Moon’s Importance Scientists theorize that without our Moon

there may not be humans on Earth Moon stabilizes Earth’s axial tilt Without our Moon the Earth have drastic

weather changes

Bark at the Moon

If We Had No Moon Video Quiz

12. Add question #12 What happens to the body without gravity for a long period of time?

The features of the Moon include:Craters, Marias, Highlands, and Mountains

Did you know the last man on the moon, Gene Cernan, wrote his daughter’s initials on the lunar surface.

Moon Map Activity

Moon Map ActivityRevise the following questions:

4.Identify the largest mare.5.How many men have walked on the lunar surface?7. List 5 interesting Lunar Facts not covered in the notes.

Moon’s Motions The Moon revolves around the Earth

counterclockwise in an elliptical orbit

Apogee

Apogee= Away from Earth (distance 252,000 miles

Slowest Velocity

• Apparent Diameter of Moon: Looks Smaller• Pull of Gravity: Less

Perigee

Perigee= Closest to Earth (distance 223,000 miles

Fastest Velocity

• Pull of Gravity: More• Apparent Diameter of Moon: Looks Larger

The apparent difference in Lunar size from Perigee to Apogee

Why do we Always See the Same Side of the Moon?

The rotation period of the Moon, with respect to the universe, is exactly the same as the revolution period of the Moon around the Earth.

Is this a coincidence? No! It’s due to Tidal Locking

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Synchronous Motion Because Moon’s period of revolution and

rotation are identical, we view only the near side of the Moon. Never the far side!

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Lunar Phases

This causes the “phases” of the Moon Waxing Moon – increasing from day to day Waning Moon – decreasing from day to day

Sunlight illuminates half of the Moon• it’s a ball and the Sun is

shining on it from one direction

Lunar Cycle 29.5 Days = Synodic Month or Lunar

Month the time it takes the moon to go through its full cycle of phases. For example full to full.

Sidereal Month 27.3 time it takes for the moon to complete 1 full revolution around Earth in relation to the background stars.

Cycle of Lunar Phases

Takes 29.53 days This is because when moon gets back to its

original position in 27.3 days, the earth has moved 1°/day or about 27°.

The moon moving at l3°/day takes about 2 days to catch up with Earth and align with it and the sun in a new moon phase.

Sidereal vs. Lunar CycleSidereal vs. Lunar Cycle

Moon Stick DemoMoon Stick Demo

Moon Phases Definition- the cyclic apparent changing of

the shape of the Moon Occurs because Moon revolves around

Earth and when viewed from Earth we see different amounts of the sunlit portion of the Moon

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Moon Phases

Half of the moon is always receiving light from the sun.

The “lit” portion that is visible to earth varies as the moon REVOLVES around earth. THIS CAUSES THE PHASES OF THE MOON.

Visible portion of moon growing = waxing Visible portion of moon shrinking = waning

Vocabulary Page 2

The Phase of the Moon

The phase of the Moon depends on the relative position between the Sun, the Earth, and the Moon…

Lunar Phases

Phases of the MoonPhases of the MoonDefinition: Apparent change of the shape of the Moon.Definition: Apparent change of the shape of the Moon.1. Caused by 1. Caused by ________________________________________________________________________

2. Our Earth view of the changing2. Our Earth view of the changing__________________________________________________________________

We see the moon because the sun is reflecting off of it.We see the moon because the sun is reflecting off of it.

WaxingWaxing: increasing the sunlit portion of the Moon that : increasing the sunlit portion of the Moon that you see from Earth.you see from Earth.

WaningWaning: decreasing the sunlit portion of the Moon : decreasing the sunlit portion of the Moon that you see from Earth.that you see from Earth.

the moon’s revolution around the Earth

illuminated part of the moon’s surface

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Phases of the Moon Rap

Identify the Phase

Waxing Crescent

Identify the Phase

First Quarter

Identify the Phase

Waning Gibbous

Lunar Cycle 29.5 Days = Synodic Month or Lunar

Month the time it takes the moon to go through its full cycle of phases. For example full to full.

Sidereal Month 27.3 time it takes for the moon to complete 1 full revolution around Earth in relation to the background stars.

Cycle of Lunar Phases

Takes 29.53 daysThis is because when moon gets back to its

original position in 27.3 days, the earth has moved 1°/day or about 27°.

The moon moving at l3°/day takes about 2 days to catch up with Earth and align with it and the sun in a new moon phase.

Blue Moon

What is a Blue Moon?

The second full moon in the same month

Lunar Eclipse Moon goes into Earth’s Shadow Can only happen in the Full Moon Phase Total eclipse lasts for 100 minutes Happens 2 times a year Can be witnessed by many people Winter Solstice Eclipses-2010 Lunar Eclipses-4:16 Slooh.com

Lunar Eclipse

Solar Eclipse Moon blocks out sunlight from reaching

Earth Day turns to night Total Solar Eclipse lasts for 7.5 minutes New Moon Phase Rare 1 every 200 years for a particular

location Moon Dance Slow-Quad-total lunar eclipse 12/20/2010

Solar Eclipse

Bailey’s Beads

Solar Eclipse- Side, Turkey-2006

Annular Solar Eclipse Moon does not totally obscure the face of

the Sun. Why?

Total Solar Eclipse of 21 June 2001 from Zimbabwe

See Richard Monk’swebpage on eclipses:www.williams.edu/astronomy/IAU_eclipses/

Bailey’s Beads

Solar Corona

“Diamond Ring”

Solar Eclipse ForecastSolar eclipses from 2004 to 2030

Knowing the orbit of the Earth and the Moon, we can now calculate the time and path of solar eclipses with great accuracy.

The Cause of Eclipses: Shadows

Lunar Eclipses

Solar Eclipses

Solar Eclipses Occur when moon’s orbit intersects ecliptic

during the new moon phase

Total Solar Eclipses only last about 7 minutes in a very narrow range

across Earth

Eclipse facts

• Lunar eclipses can only occur during a full moon.

• Solar eclipses can only occur during a new moon.

• A Solar eclipse always occurs two weeks before or after a lunar eclipse.

• Eclipses very often occur in threes, alternating lunar, solar and lunar.

Eclipse facts

• The maximum time a lunar eclipse can last is 3 hours and 40 minutes.

• The longest time the Moon can stay in totality is 1 hour 40 minutes.

• The maximum time for a total solar eclipse is 7 minutes and 40 seconds.

• The maximum time for an annular solar eclipse is 12 minutes 24 seconds.

• Lunar eclipses can occur up to 3 times a year.

Eclipse facts

• Solar eclipses can occur at least 2 and no more than 5 times a year.

• Lunar eclipses are visible over an entire hemisphere.

• Solar eclipses are visible in a narrow path a maximum of 167 miles wide (269km.)

• At any geographic position on the Earth, a total solar eclipse occur an average of once every 360 years.

Eclipse facts

• The cycle of eclipses repeats every 18.6 years called the saros.

• The eclipse shadow moves at 2,000 mph at the Earth's poles and 1,000 mph at the Earth's equator.

Uniform water level

Moon

Moon’s orbit

The twice-daily rise and fall of Earth’s oceans—

known as the tide—is a result of gravitational pulls

from the moon and the sun.

VOCABULARY

TidesThe Moving Ocean

Low tide

Low tide

Direct high tide

Indirect high tide

tides

perigee

apogee

Tides reach different levels depending on Earth’s location in relation to the moon and sun.• High tides are higher and low tides are lower when the moon, sun, and Earth are aligned.• High tides are not as high and low tides are not as low as usual when the moon and sun are not in line with Earth.

VOCABULARY

Tides

The Moving Ocean

The twice-daily rise and fall of Earth’s oceans—

known as the tide—is a result of gravitational

pulls from the moon and the sun.

tides

perigee

apogee

Earth

Moon Moon

Spring Tides

The gravitational affects of the moon and sun combine to influence the flow of the oceans on Earth.

New MoonPhase of the moon?

Full Moon

Phase of the moon?

Moon

New Moon

Phase of the moon?

Higher high tides and lower low tides

Spring Tides Occurs when the Earth, Moon, and Sun are

all aligned in a straight line. Can only occur in the Full and New Moon

phases Strong tides- Higher than normal high tides

and lower than normal low tides (large tidal range)

Earth

Moon

MoonFirst Quarter

Phase of the moon?

Third Quarter

Phase of the moon?

Neap Tides

The gravitational affects of the moon and sun fight each other with their influence on the flow of the oceans on Earth.

Moon

Third Quarter

Phase of the moon?

Lowest high tides and highest low tides

Neap Tides Occurs when the Earth, Moon, and Sun are

aligned at a 90° angle. Can only occur in the Quarter Moon phases Weak tides- Lower than normal high tides

and higher than normal low tides (small tidal range)

Moonlight Drive- Doors

Tides• Perigee: The point

closest to Earth in the moon’s orbit.

• Apogee: The point farthest to Earth in the moon’s orbit.

Daily Cycle of Tides

Driven by the gravitational pull of the moon and Sun

Affected by nearness of the moon more than the size of

the Sun

As earth rotates, the tides move around the Earth

alternating between high and low tides approximately

every 6 hours.

Man on the Moon

Tides Definition- the periodic rising and falling of

the oceans Caused by the Moon’s gravity Affected by the Earth’s rotation 2 types- Spring and Neap

Spring Tides – Neap Tides

Tidal range: Difference in height between high tide and low tide

Spring Tides: new and full moon phase – greatestrange

Neap Tides: 1st and 3rd Quarter phases – smallestrange