The MoonThe Moon

MOON:MOON:

• a natural satellite of a planet

• may vary widely in composition

The Earth’s MoonThe Earth’s Moon

• Lunar rocks brought back during Apollo missions found to be 4.6 billion years old…a clue to the age of the Earth and of our solar system…

Exploring the MoonExploring the Moon

•1957: Soviet Union launched Sputnik I, the first artificial satellite

Exploring the Moon…Exploring the Moon…

• 1961: Yuri A. Gagarin, Soviet cosmonaut, became first human in space

• 1962: Project Mercury: Alan B. Shepard, Jr., first American in space

• Project Gemini: launched 2-person crews

Apollo 11Apollo 11• July 20, 1969

• First manned mission to landland on the moon

• Neil ArmstrongArmstrong and Edwin “Buzz” Aldrin

I. Formation of the MoonI. Formation of the Moon

Giant-Impact Hypothesis:

Mars-sized body struck the Earth early in its history

Collision caused an ejection of fragments into orbit around Earth

Fragments eventually joined to form the moon

Supported by silica-rich samples of moon rocks brought back by Apollo astronauts

• Moon Impact Theory

II. Movements of the MoonII. Movements of the Moon• The orbit of the moon around Earth is an

ellipse– Apogee: when the moon is furthest away from

Earth– Perigee: when the moon is closest to Earth

http://upload.wikimedia.org/wikipedia/commons/5/59/Orbit3.gif

ROTATION and REVOLUTION ROTATION and REVOLUTION Periods are Periods are EQUALEQUAL

• Revolution around the Earth: 27.3 days– Revolution around Earth creates

moon phases and eclipses

• Rotation on its axis: one rotation during each orbit around the Earth

A. TidesA. Tides

• The daily, periodic rise and fall of Earth’s water levels caused by the gravitational attraction between the Earth and moon

• Two (2) high and low tides each day

• Create a bulge of land and water on one side of the Earth

SPRING SPRING TIDES:TIDES:

higher high tides and lower low tides at

FULL and NEW moon phases

• During SPRING TIDES:

• The SUN, MOON,

EARTH form a

LINE

• To SPRING means:

“to jump” or

“to leap up”

• NEAP TIDES: weak tides; tidal

ranges at a minimum

• occur during QUARTER

moons

B. EclipsesB. Eclipses

1. SOLAR Eclipse: MOON is between the Earth and the Sun and blocks out the Sun.

2. LUNAR Eclipse: EARTH is between the moon and the Sun and

Earth’s shadow blocks out the moon.

•

• EclipsesEclipses

What makes the moon shine?What makes the moon shine?

III. Lunar Cycle: III. Lunar Cycle: Phases of the MoonPhases of the Moon

NEW Moon: moon is not illuminated (lit)

FULL Moon: full lighted circle

• Earth is between the moon and the sun

WAXINGWAXING Moon: size of the visible portion of the moon increasesincreases

WANINGWANING Moon: size of the

visible portion of the moon decreases

Lunar MonthLunar Month

• SynodicSynodic month: measured from new moon to new moon = 29.5329.53 days

• SiderealSidereal month: orbital period = 27.3227.32 days

Sidereal vs. Synodic PeriodsSidereal vs. Synodic Periods

• Phases of the MoonPhases of the Moon

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