The Moon's Origin and Characteristics
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Arny, 3 rd Edition, Chapter 3
description
The Moon's Origin and Characteristics. Arny , 3 rd Edition, Chapter 3. Motivation. How do you think the Moon was created?. Moonset on a clear desert morning. OBJECTIVES. Describe the theories of the Moon’s origins. Define and summarize the favored theory of the Moon’s origin. - PowerPoint PPT Presentation
Transcript of The Moon's Origin and Characteristics
Arny, 3rd Edition, Chapter 3
The MoonThe MoonLesson 12: Chap 3, Sec 3.3 and 3.6 The Lesson 12: Chap 3, Sec 3.3 and 3.6 The
Moon's Motions and Influence on TidesMoon's Motions and Influence on Tides 22
How do you think the Moon was created?
Moonset on a clear desert morning
Describe the theories of the Moon’s origins.Define and summarize the favored theory of the Moon’s
origin.Analyze how the evidence supports the different theories
of the Moon’s origin.What is the Moon’s size and composition?How does the Moon compare and contrast with the Earth?What is the Moon’s atmosphere like?
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DebrisBasinsVaporizedSimulation
Captured PlanetTwin of Earth, forming side by sideRapid spinning Earth threw off chunk
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Impact of Mars sized planetMelted and
vaporized materials
Left Earth’s core mostly intact
Explains both similarities and differences in composition
Could explain Earth’s tilted axis
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CollisionEjected debrisMolten Moon starts to coolSmall asteroids from collision
cause craters that blanket highlands regions
Larger asteroids formed maria basins which flooded with lava
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What do you think the differences would be on Earth if we had no Moon?
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Apollo Moon landings (1969-1972)6 landings, 12 men walked on the Moon
What value was gained?
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Moon has ¼ the Earth’s diameter and circumferenceMoon has 1/10 the Earth’s mass
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12,800 km or 8,000 mi diameter40,000 km or 25,000 mi
circumference
3,500 km diameter2,200 mi
6,800 mi circumference11,000 km
Moon’s interior is nearly inactive.
What explains this inactivity?
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Faster coolingLess natural radioactive material to supply
heat affects motions in interior and on surface
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Anything similar?CoreMantleCrust
Anything different?SymmetryLiquid regionsSize
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Is there a magnetic field? Why? Is there an atmosphere?How does its small size affect
characteristics?Are there volcanoes or moonquakes?
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No magnetic fieldSmall size, little iron in
the core, lack of liquid core and internal rotation
No plate tectonics
Lack of atmosphere called a vacuumExtreme temperatures
No volcanic activity to supply gases, plus weak gravity cannot hold gases
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VERY hot in the sun
VERY cold in the shade
Constant or varying appearance?
What are its major regions?
What other surface features are in these regions?
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Highlands
Maria
Major regions:Highlands – hilly, light-colored
regions, heavily crateredMaria – look like “seas”; dark,
congealed lava regionsThe Moon has other surface
features:Craters – made by impactsRays – shattered rock thrown
from crater formationRilles - canyons formed from
cooling or lava flowsRegolith – fine, powdery soil
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Craters
Rays
Rille
Desolate surface Unchanged for a long time
No wind, weather, erosion or other forces to change appearance
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Define and summarize the favored theory of the Moon’s origin.
How big is the Moon?¼ Earth’s diameter and
circumferenceHow does the Moon’s composition
compare and contrast with the Earth’s?Nearly inactiveNot as much iron in coreDifferentiated by Earth’s gravity
How did the Moon’s size affect its internal heat?Faster coolingLess internal heat 1919
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Why does the Moon have no magnetic field?Smaller size, less iron in the core, no liquid core
or internal rotationWhy does the Moon have no atmosphere?
No volcanoes, no gasesWeaker gravity
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What does the Moon’s surface look like? Desolate Two major regions:
Highlands Maria
Other surface features: Craters Rays Rilles Regolith
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How big is the Moon? How is the Moon’s interior different from
the Earth’s interior? Why doesn’t the Moon experience plate
tectonics? What are the lunar surface’s two main
regions? What are craters, rays, and rilles? What is regolith?
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The Moon’s diameter is ____ the Earth’s diameter.
The Moon’s surface layer consists of shattered rock chunks and powder from ________ _______.
Some molten material may be below the Moon’s mantle, but its _____ is smaller and contains less iron and nickel than Earth’s.
The Moon doesn’t have a ________ ______ because its core is small, has little iron, and probably doesn’t rotate much.
Because the Earth’s atmosphere is a ___________, the Moon’s surface gets very hot during the day and very cold at night.
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The two main regions of the Moon’s surface are ______ and _______.
The __________ on the Moon are bright rugged areas pitted with craters.
The _________ are large, smooth, dark areas on the Moon’s surface.
Circular features on the Moon’s surface with a raised rim caused by meteor impacts are called ___________.
__________ are long, light streaks of pulverized rock radiating away from many craters on the Moon’s surface.
Canyons caused by cracking during cooling and lava flows are called ___________________.
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Define and summarize the favored theory of the Moon’s origin.
How does the Moon’s size and composition compare and contrast with the Earth’s?
What effect does this difference have? What is the Moon’s surface like?What processes created the surface features?
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Done—the Moon’s origin and characteristics
Next—the Moon’s motions in space and relationship to ocean tides
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Arny, 3rd Edition, Chapter 3
QUESTIONS?QUESTIONS?
