Ch. 1Ch. 1Sec. 4 Earth’s MoonSec. 4 Earth’s Moon

Activity-Why do craters look Activity-Why do craters look different from each other?different from each other?

Object Object Diameter of Diameter of circle- 20 cmcircle- 20 cm

Diameter of Diameter of circle- 50 cm circle- 50 cm

Diameter of Diameter of circle- 100 cmcircle- 100 cm

(1 m)(1 m)

Small Small marblemarble

Large Large marblemarble

Rubber Rubber ballball

Which object left the largest crater? Which object left the deepest crater?

Features on the moon’s surface include craters, highlands, and maria.

Astronomers have given names to many of the moon’s craters and maria.

features onMoon’s surfaceseen by Galileowith telescope

craterscraters highlandshighlands mariamaria

round pits formed by

meteoroid impactsnot volcanoes

mountains• dark, flat areas-ancient lava flows• once thought to be ancient seas

Ocean of

Storms

Sea of Tranquility

Mooncharacteristics

size & size & densitydensity

temp. & temp. & atmos.atmos. waterwater

• ¼ Earth’s diameter

•1/80 Earth’s mass

130oC -180oC

dry & airless

• no liquid water• may have ice

No atmosphere

collision-ring theorycollision-ring theory

best theory of moon’s originbest theory of moon’s origin

1.1. 4.5 billion yrs. ago- planet 4.5 billion yrs. ago- planet sized object hit Earth sized object hit Earth

2. material from Earth’s outer 2. material from Earth’s outer layer broke off layer broke off 3. material thrown into orbit3. material thrown into orbit4. formed moon4. formed moon

Time to Time to ReviewReview

Name 3 major features of Name 3 major features of the moon’s surface.the moon’s surface.

1.1. craterscraters

2.2. mariamaria

3.3. highlandshighlands

How did the moon’s How did the moon’s craters form?craters form?

meteoroid meteoroid

impactsimpacts

Why is the moon’s surface Why is the moon’s surface much more heavily cratered much more heavily cratered

than Earth’s surface?than Earth’s surface?

Water, wind, and other Water, wind, and other forces wore away craters on forces wore away craters on Earth. There is no wind or Earth. There is no wind or liquid water on the moon.liquid water on the moon.

Describe the range of Describe the range of temperatures on the moon.temperatures on the moon.

130oC to -180oC

(266oF to -292oF)

What is the relationship What is the relationship between the moon’s surface between the moon’s surface

gravity, lack of an atmosphere, gravity, lack of an atmosphere, and temperature range?and temperature range?

The moon’s weak surface gravity The moon’s weak surface gravity allows gases to escape into allows gases to escape into space, so the moon has no space, so the moon has no

atmosphere, resulting in widely atmosphere, resulting in widely varying surface temperatures.varying surface temperatures.

What was the solar What was the solar system like when the system like when the

moon formed?moon formed?

The solar system was The solar system was full of rocky debris.full of rocky debris.

Explain the various stages in Explain the various stages in the formation of the moon.the formation of the moon.

1.1. A planet-sized object collided A planet-sized object collided with Earth. with Earth.

2.2. Material was ejected into orbit Material was ejected into orbit around Earth and formed a ring. around Earth and formed a ring.

3.3. Gravity caused this material to Gravity caused this material to combine into the moon.combine into the moon.