Key Vocabulary Terms

gravity - force of attraction between any two objects.
mass - amount of matter that an objects contains.
orbit - curved path that an object follows as it revolves around another object.

Key Concepts

The force of attraction between two objects, causing them to be pulled toward each other is gravity.
Gravity's force depends on how close the two objects are to each other and how much mass each object has.
The curved path of an object as it revolves around another object is an orbit.
Gravity pulls the earth into orbit around the sun.
The moon orbits the earth; the earth, with the moon, orbits the sun.

Did you learn these Objectives?

Can you explain what gravity is?
Are you able to name the factors that affect the strength of gravity?
Are your able to describe how gravity affects the moon and the earth?

Investigation 3-1 "Making a Model of an Orbit" (Optional, must complete 16 total investigations)

Key Concepts

You will create a tool that will help you to model an orbit so that you will understand the orbit better.

Lesson 2 "The Earth's Movement in Space"

Key Vocabulary Terms

revolution - movement of one object in its orbit around another object in space.

Key Concepts

A year is 365 days long because that is how long it takes the earth to revolve once around the sun.
The Earth is tilted on its axis 23.5 degrees.
When the Northern Hemisphere is tilted toward the sun, it is summer there.
When the Northern Hemisphere is tilted toward the sun it is winter in the Southern Hemisphere.
Direct sunlight strikes the earth head-on, at an angle close to 90 degree; indirect sunlight strikes the earth at a lesser angle.

Did you learn these Objectives?

Can you describe the movement of the earth around the sun?
Are your able to explain how the earth's revolution and the tilt of its axis cause seasons?

Investigation 3-2 "Exploring Light Angle" (Optional, must complete 16 total investigations)

Key Concepts

You will model and determine how the angle of sunlight affects the strength of the light.

Lesson 3"The Moon's Movement in Space"

Key Vocabulary Terms

phases of the moon - changes in the moon's appearance as it orbits the earth.
full moon - phase of the moon when the earth is between the sun and the moon.
new moon - phase of the moon when the moon is between the sun and the earth.
solar eclipse - passing of the moon between the earth and the sun.
lunar eclipse passing of the moon through the earth's shadow.
tides - regular rising and falling of the earth's major bodies of water.

Key Concepts

The moon rotates once in the same amount of time that it revolves once around the earth. Therefore, the same side always faces the earth.
The moon shines because it reflects light from the sun back to the earth.
A full moon occurs when the side of the moon facing the earth is fully lit by the sun. A new moon occurs when the moon is between the sun and the earth; the side of the moon facing the earth appears dark. Other phases occur as the moon moves around the earth, showing different amounts of its sunlit side.
A solar eclipse occurs when the moon is between the earth and the sun. A lunar eclipse occurs when the earth is between the moon and the sun.
Tides are caused when the moon's gravitational pull lifts water of the earth's oceans.

Did you learn these Objectives?

Can you describe the rotation of the moon?
Are you able to explain the phases of the moon?
Can you explain how the moon helps cause tides?
Are you able to explain why eclipses occur?

Lesson 4 "The Moon's Surface"

Key Vocabulary Terms

Telescope - instrument that collects light, making faint objects easier to see and enlarging distant objects.
maria - low, flat plains on the moon's surface that appear as dark areas.
crater - circular low area surrounded by a rim, usually caused by an object hitting the ground.
meteorite - piece of rock that hits the surface of a planet or moon after traveling through space.

Key Concepts

The dark areas are flat plains called maria and light areas on the surface of the moon highlands.
The craters formed on the moon are caused by rocks called meteorites hitting the surface, causing an explosion that blasts away rocky material, leaving a rimmed depression.
The first person walked on the moon July 20, 1969, three months after I was born.
The moon is about 400,000 kilometers from the earth.
The Apollo space mission enabled scientists to learn about the moon's surface and interior, calculated the moon's approximate age, and learned about the geologic and radiation history of the moon by collecting photos, moon rocks, and experiment results the missions brought back.

Did you learn these Objectives?

Are you able to describe physical features of the moon.
Can you tell when astronauts visited the moon and what their missions accomplished?

Chapter Summary and Review

See page 74-75.

Chapter 1 Review answers are

1. revolution

2.mass

3.solar eclipse

4 .gravity

5. tides.

6. gravity.

7. orbit.

8. meteorite.

9. lunar eclipse.

10. maria.

11. The earth rotates, or spins, on its axis. One rotation takes about 2 hours, or one day. The earth revolves in an orbit around the sun. One revolution takes about 36 days, or one year.

12. The earth.

13. A third quarter, B full moon, C new moon, D first quarter.

14. Apollo.

15. A.

16. D.

17. C.

18. It always faces away from the earth, so it is less protected and more vulnerable to asteroids coming from beyond the earth's orbit.

19. a lunar eclipse occurs because the earth is between the moon and the sun, and the earth casts a shadow on the moon. A new moon occurs because the moon is between the sun and the earth. Therefore, the side of the moon lit by the sun is turned away from the earth and cannot be seen.

20. The moon might orbit at a greater distance from the earth, or if the force were reduced enough, the moon would fly off into space.