1. CHAPTER
NEW CHAPTER
Earth, Moon, and Sun
the BIG idea
Earth and the Moon move in predictable ways as they orbit the Sun.
2.1
Earth rotates on a tilted axis and orbits the Sun.
2.2
The Moon is Earth’s natural satellite.
2.3
Positions of the Sun and Moon affect Earth.
CHAPTER OUTLINE

2. Earth rotates on a tilted axis and orbits the Sun.
2.1
Earth rotates on a tilted axis and orbits the Sun.
Earth’s rotation in sunlight causes day and night.
The changing angles of sunlight on Earth cause seasons.
axis of rotation
revolution
season
equinox
solstice
SECTION
OUTLINE

3. 2.1
Earth rotates on a tilted axis and orbits the Sun.
axis of rotation
axis of rotation
revolution
season
An imaginary line about which a turning body, such as Earth rotates.
equinox
solstice
KEY CONCEPT
SUMMARY

4. 2.1 revolution Earth rotates on a tilted axis and orbits the Sun.
axis of rotation
revolution
revolution
season
The motion of one body around another, such as Earth in its orbit around the Sun; the time it takes an object to go around once.
equinox
solstice
KEY CONCEPT
SUMMARY

5. 2.1 season Earth rotates on a tilted axis and orbits the Sun.
axis of rotation
season
revolution
season
One part of a pattern of temperature changes and other weather trends over the course of a year. Astronomical seasons are defined and caused by the position of Earth’s axis relative to the direction of sunlight.
equinox
solstice
KEY CONCEPT
SUMMARY

6. 2.1 equinox Earth rotates on a tilted axis and orbits the Sun.
axis of rotation
equinox
revolution
season
In an orbit, a position and time in which sunlight shines equally on the Northern Hemisphere and the Southern Hemisphere; a time of year when daylight and darkness are nearly equal for most of Earth.
equinox
solstice
KEY CONCEPT
SUMMARY

7. 2.1 solstice Earth rotates on a tilted axis and orbits the Sun.
axis of rotation
solstice
revolution
season
In an orbit, a position and time during which one hemisphere gets its maximum area of sunlight, while the other hemisphere gets its minimum amount; the time of year when days are either longest or shortest, and the angle of sunlight reaches its maximum or minimum.
equinox
solstice
KEY CONCEPT
SUMMARY

8. The Moon is Earth’s natural satellite.
2.2
The Moon is Earth’s natural satellite.
The Moon’s near side always faces Earth.
mare
Dark-colored maria formed from
lava-filled craters.
Light-colored highlands are old and cratered.
SECTION
OUTLINE

9. The Moon is Earth’s natural satellite.
2.2
The Moon is Earth’s natural satellite.
The Moon’s near side always faces Earth.
mare
The Moon has layers.
crust
mantle
core
SECTION
OUTLINE

10. 2.2 mare The Moon is Earth’s natural satellite.
A large, dark plain of solidified lava on the Moon. The plural form of mare is maria.
KEY CONCEPT
SUMMARY

11. Positions of the Sun and Moon affect Earth.
2.3
Positions of the Sun and Moon affect Earth.
Lunar phases are different views of the Moon’s sunlit half.
eclipse
umbra
penumbra
Moon
Earth
SECTION
OUTLINE

12. Positions of the Sun and Moon affect Earth.
2.3
Positions of the Sun and Moon affect Earth.
Lunar phases are different views of the Moon’s sunlit half.
eclipse
Shadows cause eclipses.
umbra
penumbra
umbra
penumbra
SECTION
OUTLINE

13. Positions of the Sun and Moon affect Earth.
2.3
Positions of the Sun and Moon affect Earth.
Lunar phases are different views of the Moon’s sunlit half.
eclipse
Shadows cause eclipses.
umbra
The Moon’s gravity causes tides as Earth turns.
penumbra
Moon
low tide
High tide
rotation of Earth
SECTION
OUTLINE

14. 2.3 eclipse Positions of the Sun and Moon affect Earth.
umbra
An event during which one object in space casts a shadow onto another. On Earth, a lunar eclipse occurs when the Moon moves through Earth’s shadow, and a solar eclipse occurs when the Moon’s shadow crosses Earth.
penumbra
KEY CONCEPT
SUMMARY

15. 2.3 umbra Positions of the Sun and Moon affect Earth.
eclipse
umbra
umbra
The dark, central region of a shadow, such as the cone of complete shadow cast by an object.
penumbra
KEY CONCEPT
SUMMARY

16. 2.3 penumbra Positions of the Sun and Moon affect Earth.
eclipse
penumbra
umbra
A region of lighter shadow that may surround an umbra; for example, the spreading cone of lighter shadow cast by a space object.
penumbra
KEY CONCEPT
SUMMARY

17. 2.1 Earth rotates on a tilted axis and orbits the Sun.
I. Earth rotates on a tilted axis and orbits the Sun.
axis of rotation
A. Earth’s rotation causes day and night.
revolution
B. Earth’s tilted axis and orbit cause seasons.
season
equinox
1. Seasonal Patterns
solstice
2. Angles of Sunlight
3. Lengths of Days
KEY CONCEPT
SUMMARY

18. The Moon is Earth’s natural satellite.
2.2
The Moon is Earth’s natural satellite.
II. The Moon is Earth’s natural satellite.
mare
A. The Moon rotates as it orbits Earth.
B. The Moon’s craters show its history.
1. Craters and Maria
2. Moon Rocks
C. The Moon has layers.
1. Structure
2. Formation
KEY CONCEPT
SUMMARY

19. Positions of the Sun and Moon affect Earth.
2.3
Positions of the Sun and Moon affect Earth.
III. Positions of the Sun and Moon affect Earth.
eclipse
A. Phases are different views of the Moon’s sunlit half.
umbra
1. Waxing Moon
penumbra
2. Waning Moon
3. Crescent and Gibbous Moons
B. Shadows in space cause eclipses.
1. Lunar Eclipses
2. Solar Eclipses
C. The Moon’s gravity causes tides on Earth.
KEY CONCEPT
SUMMARY