1. Sun, Moon, and Earth

2. Earth Rotation- Earth spinning on its axis
Axis- imaginary line that passes through Earth’s center from north to south poles
Rotation causes day and night (clockwise- east to west)
Takes Earth 24 hours (1 day) to rotate once on its axis

3. Earth Revolution- movement of one object around another object
One complete revolution around the sun= 1 year
Earth’s path as it revolves around the sun; orbit which is elliptical (oval)
Orbit- the path an object takes around another during a revolution

4. Earth
Calendar
Earth’s orbit around the sun takes about 365 ¼ days ( days) or 1 year
Leap year every 4 years we make up the extra day. February has 29 days in leap year. (4 x ¼ =1)
The time between one full moon and the next is about 29 ¼ days

5. Seasons
Latitude- Distance north or south from the equator; measured in degrees
Equator gets more solar energy (radiation)- straight sun rays
Higher latitudes are colder- angled sun rays

6. Seasons
Earth’s tilt is 23.5˚ North or South making the axis tilt toward the sun part of the year and away from the sun the other part; always points toward the north star
Seasons are determined by how light hits Earth

7. Seasons

8. Seasons
When north is tilted toward the sun, Northern Hemisphere has summer, Southern has winter
When Northern Hemisphere is tilted away from sun, has winter, Southern has summer
Solstice- the two days of the year when the sun is directly overhead

9. Seasons
Summer- Northern Hemisphere is tilted toward the sun; more hours of daylight
June- Summer solstice, longest day of the year, June 21, first day of summer

10. Seasons
Winter- Northern hemisphere tilted away from sun, less hours of day light
December- Winter solstice; shortest day of the year, December 21, first day of winter

11. Seasons

12. Seasons Equinox- equal day and night, sun directly above the equator;
March 21- Vernal equinox, spring
September 23- Autumnal equinox, fall

13. Moon The moon is a satellite of Earth: it revolves around the Earth
Moon has almost no atmosphere
Surface- detailed study of moon rocks gathered by astronauts
Craters- cover much of the moon’s surface
Highlands- mountains
Maria- once flooded with molten material; appear as dark, flat areas

14. Moon
The position of the moon, Earth, and the sun cause the phases of the moon, eclipses, and tides.
The moon’s movement
Moon’s revolution is about 27.3 days
Moon’s rotation is about 27.3 days
The moon’s “year” and “day” take the same amount of time.
The “far side” of the moon always faces away from Earth; you never see it.

15. Moon Gravitational pull- the moon and Earth both pull on each other
Moon’s density is about the same density as Earth’s outer layers
Formation- Collision Theory- states that about 4.5 billion years ago a large object collided with Earth; material from this collision was thrown into orbit around Earth, eventually forming the moon.

16. Moon Phases
Phases: the different shapes of the moon that we see from Earth
What causes the phases?
The moon reflects light from the sun; half of the moon is always lit, and half is dark.
The amount of sunlit side of the moon that faces Earth
As the moon revolves around Earth, the light side of the moon rotates around, changing the amount we see from Earth.

17. Moon Phases Full- the entire lit side of the moon is seen
Gibbous- over half of the lit side is seen
Quarter- you can only see half of the lit side of the moon (1st and 3rd/Last)
Crescent- less than half of the lit side is seen; thumbnail shaped
New- the entire dark side is seen

18. Moon Phases
It takes about 29.5 days from one new moon to the next : 1 complete cycle
Waxing- the amount of lit side of the moon seen is increasing
Waning- the amount of lit side of the moon seen is decreasing

19. Moon Phases

20. Tides Tide- the daily rise and fall of Earth’s coastlines
Tidal bulge- the moon’s gravitational pull on the water at the point closest to the moon, and on the opposite side creates a bulge of water; high tide
Low tide- the points between the high tide points have low tide.
There are 4 tides a day; 2 high and 2 low

21. Tides
Spring tide- at the new and full moons, the sun and moon are lined up. Their combined gravitational pull creates the biggest difference between high and low tides.
Neap tide- at the 1st and 3rd quarters of the moon, the sun and moon pull at right angles to each other. This makes the least difference between the high and low tides.

22. Tides

23. Tides

24. Eclipses
When the moon’s shadow hits Earth or the Earth’s shadow hits the moon
Solar Eclipse- the moon passes between Earth and the sun casting a shadow on the Earth; a new moon in which the moon blocks the view of the sun.
Lunar Eclipse- when the Earth passes between the sun and the moon

25. Eclipses Lunar Eclipse
Umbra - darkest part of a shadow Penumbra- part of the shadow surrounding the darkest part

26. Eclipses

27. Sun Energy from the sun lights and heats Earth’s surface
The only star in our solar system
Is a yellow Dwarf star
The corona forms the sun’s outer atmosphere
The photosphere is the visible part of the sun that we see from Earth.
The core is where the sun’s energy is produced.

28. Sun