1. Earth Science Notes
The Earth, Moon, and Sun

2. Properties of the Earth
Rotation refers to the spinning of earth on its axis
When Earth spins on axis it causes day and night

3. Properties of the Earth
Revolution refers to the orbiting of earth around the sun
Earth’s orbit is an ellipse

4. Properties of the Earth
Change in seasons are caused by the tilt of the earths axis as it revolves around the sun
The hemisphere that is tilted toward the sun received more sunlight (has longer days)

5. The Seasons

6. Properties of the Earth
Solstice is the day the sun reaches its greatest distance north or south of the equator
Winter solstice and summer solstice

7. Properties of the Earth
Equinoxes occur when the sun is directly above the Earth’s equator
Sunlight hours are equal during this time
Fall and Spring Equinox

8. Properties of the Earth
The earth bulges slightly at the equator
Gravity contracts earth into sphere
Rotation cause Earth’s sphere to bulge
Pull of moon creates tidal bulge

9. Properties of the Earth
Earth has a magnetic poles
Moving material inside the earth as well as Earth’s rotation may generate the magnetic field
The poles change over time
Recall magnetic reversals as evidence of seafloor spreading

10. The Moon
Moon phases
Different forms that the moon takes in appearance

11. The Moon
Moon Phases - depend on the relative position of the Earth, Moon, and Sun.
New Moon  Moon is between earth and the sun – no light is reflected
Waxing Crescent  first thumbnail shaped portion of the moon seen
First Quarter  one quarter of the moon is reflecting the sun light
Waxing Gibbous  means more of the illuminated half can be seen each night

12. Moon Phases

13. Moon Phases (cont.)
Full Moon  moon surface that faces earth reflects all light from sun
Waning Gibbous  means less of the illuminated half can be seen each night
Third Quarter  one quarter of the moon is reflecting the sun light
Waning Crescent  last thumbnail shaped portion of the moon seen

14. Moon Phases

15. The Moon
Solar eclipse occurs when the moon moves directly between the sun and the earth.

16. Solar Eclipse

17. The Moon
Lunar eclipse occurs when the earth falls directly between the sun and the moon

18. The Moon Structure of the moon
Models for moon’s interior derived from seismic activity (i.e. moonquakes)
The moon is made up of crust, upper mantle, lower mantle, and core.

19. The Moon Origin of the Moon
Various theories had been proposed for the formation of the Moon.
Fission Theory – moon somehow separated from the earth
Location – pacific basin
Evidence – moon is made of materials similar to Earth’s mantle
Problem – cast off of moon would be do to rapid spinning of Earth – no fossil evidence of this

20. The Moon Origin of the Moon
Capture Theory: Moon was formed somewhere else in the solar system, and was later captured by the gravitational field of the Earth

21. The Moon Origin of the Moon
The Condensation Theory: the Moon and the Earth condensed individually from the nebula that formed the solar system.
Problem – if the Moon formed near Earth it should have nearly the same composition. Specifically, it should possess a significant iron core, and it does not.

22. The Moon Origin of the Moon
The Giant Impactor Theory: proposes that a small planet the size of Mars struck the Earth just after the formation of the solar system, ejecting large volumes of heated material from the outer layers of both objects. A disk of orbiting material was formed, and this matter eventually stuck together to form the Moon in orbit around the Earth.
This theory can explain why the Moon is made mostly of rock and how the rock was excessively heated. Furthermore, we see evidence in many places in the solar system that such collisions were common late in the formative stages of the solar system.

23. Giant Impactor Theory

24. Click the link to learn more about these missions
Trips to the Moon
Click the link to learn more about these missions

25. The Sun
Structure of the Sun

26. The Sun Structure of the Sun
Corona – largest layer of the sun’s atmosphere, extends millions of km out into space
Chromosphere – transition zone between the photosphere and the corona
Photosphere – lowest layer of the sun’s atmosphere, where light is given off, 6000 K.

27. The Sun
Convention layer – heat energy rises and falls in this layer as gases rise, cool, and then fall
Radiation zone – energy from the suns core is transferred to the conduction zone
Core – source of suns energy, where nuclear fusion takes place

28. The Sun Surface Features of Sun
Sunspots – spots on the sun that are darker because they are cooler

29. The Sun Surface Features of Sun Prominences – arching columns of gas
Maybe caused by Sun’s magnetic field

30. The Sun
Auroras
Created as a result of electrically charged particles from the sun’s corona hitting the earth’s atmosphere and ionizing gases there.

31. The Sun
The sun is an average star. It emits average heat and light energy

32. Summary
How does rotation and revolution differ? What are the effects of each?
Explain why we have seasons.
What are the phases of the moon?
What is the difference between solar and lunar eclipses?
Explain different theories regarding the origin of the moon.
Describe the Sun’s structures and its features.