1. Earth, Moon, and Sun
Chapter 5
Lesson 1-3

2. Earth in Space
Chapter 5
Lesson 1
Page 182

3. Earth in Space Earth moves in space in 2 major ways:
rotation and revolution

4. Rotation
Axis- imaginary line that passes through Earth’s north and south pole
Rotation-spinning of Earth on its axis
Rotation causes day and night
Rotates eastward
Takes about 24 hours

5. Revolution Revolution- movement of one object around another
One revolution of Earth around the sun is called a year (that’s how long it takes)
Earth is closest to the sun in January

6. Calendar
Calendar- system of organizing time that defines beginning, length, and divisions of a year
year= time it takes Earth to complete one orbit (revolution)
Day=time it takes Earth to rotate on its axis (rotation)
Months are based on the moon phases (though it has changed in modern times)

7. What Causes Seasons?
Four distinct seasons: winter, spring, summer, & fall
Temperature difference occur (more noticeable for places away from the equator)
Sunlight directly hits at the equator and glances Earth at the poles which is why it is much warmer at the equator than the poles

8. Earth’s Tilted Access
If it weren’t for the tilted axis temperatures on Earth would remain pretty constant year-round
Earth has seasons because its axis is tilted as it revolves around the sun.
Tilted at an angle of 23.5⁰ from vertical
So at different point of the year the north pole it pointed towards the sun and 6 months later is it pointed away

9. Tilted Axis
June- north end of Earth is pointed towards the sun, so the Northern Hemisphere has more daylight hours and is experiencing the summer (southern hemisphere would be in winter)
December- North pole is pointed away so Southern Hemisphere is experiencing summer and Northern Hemisphere is experience winter

10. Solstices
Sun appears farthest north of the equator once each year and farthest south once each year
Each of these days are known as solstices
Sun appears:
Farthest North- Summer Solstice

11. Revolution Sun appears Northern Hemisphere Southern Hemisphere
We experience
Day last
Farthest North
Summer
Winter
Longer(June 21)
Farthest South
Shorter (Dec 21)

13. Equinoxes
Halfway between the solstices neither hemisphere is tilted towards that sun creating the equinoxes
Equinox- noon sun directly overhead at the equator, rises due east, and sets due west
Equal day and night (12 hours each)
Vernal (spring) March 21
Autumnal (fall) September 22

14. Phases and Eclipses
Chapter 5
Lesson 2
Page 190

15. Motions of the Moon Face on the moon is just shadows and light you see
Same side of the moon always faces the Earth
The time it takes for the moon to rotate is the same amount of time it take for it to revolve around Earth
The changing relative positions of the moon, Earth, and sun cause the phases of the moon

16. Phases of the moon
Half of the moon is almost always in sunlight, but since the moon orbits Earth, you see the moon from different angles
The phase of the moon you see depends on how much of the sunlit side of the moon faces Earth
The changes we see in the moon’s shape are called phases

17. Phases of the moon
New Moon- side of moon facing Earth is not lit, so it appears dark
As the moon revolves around Earth you see an increasing amount of the lit side of the moon until you see the whole lit side (full moon)
The moon goes through a complete set of phases in about 29.5 days

18. Phases of the moon
Notice which phases show us the same amount of the lit side of the moon

19. What are Eclipses? Read page 193
Very rarely do the sun, Earth and moon line up
Eclipse- when an object in space comes between the sun and a third object, it casts a shadow on that object
Two types:
Solar *Lunar

20. Solar Eclipses
During a new moon, the moon lies between Earth and the sun
Solar eclipse- occurs when the moon passes directly between Earth and the sun, blocking sunlight from Earth
Umbra- darkest part of the moon’s shadow
Within the umbra, sunlight is completely blocked
Penumbra-shadow the is not completely dark leaving part of the blocked solar body visible (larger than the umbra)

22. Lunar Eclipse
Lunar Eclipse- at a full moon when Earth is directly between the moon and the sun
During a lunar eclipse, Earth blocks sunlight from reaching the moon
Only occurs during a full moon because it is closets to Earth’s shadow
The moon is in Earth’s umbra- total
The moon in Earth’s penumbra- partial

23. Experiencing Total Eclipses
Anyone that can see the moon during a lunar eclipse will experience the total lunar eclipse unlike the solar eclipse where you must be in the moon’s umbra to see a total solar eclipse