1. The Sun-Earth-Moon System

2. Earth

3. Properties of Earth
The Earth is spherical – It is not a perfect sphere, though. It bulges at the equator and is flatter at the poles
2. All objects are attracted by gravity to the center of the Earth 3

4. More Properties of the Earth
3. The Earth has an axis – an imaginary vertical line around which the Earth spins
4. The spinning of Earth on its axis, or rotation, causes day and night to occur 4

5. Magnetic Field
The Earth acts as though there is a giant bar magnet inside – possibly caused by the spinning of the Earth and it’s iron based core
The Earth’s magnetic field protects us from solar radiation and solar storms
The magnetic poles are not at the geographic poles 5

6. What causes changing seasons?
Revolution – the Earth’s yearly orbit around the sun
Ellipse – the stretched out oval shape of the Earth’s orbit 6

7. A Tilted Axis
The number of daylight hours is greater for the half of the Earth that is tipped toward the sun
The tilt of the Earth causes different parts of the Earth to receive different amounts of sunlight 7

8. Vocabulary
Solstice – the day when the Sun reaches its greatest distance north or south of the equator
Equinox – the day when the Sun is directly above the equator 8

9. The Moon – Earth’s Satellite

10. Motions of the Moon
It takes 27.3 days for the Moon to rotate once on it’s axis
It takes 27.3 days for the Moon to revolve once around the Earth
So…
We always see the same side of the Moon!
The Moon appears to shine because it reflects light from the Sun 10

11. Phases of the Moon

12. Phases of the Moon
Moon phases – the different forms the Moon takes in its appearance from Earth
New Moon – occurs when the Moon is between the Earth and the Sun
A new moon occurs when the
lighted side of the moon is
facing the Sun and the dark
side is facing the Earth

13. Waxing Phases of the Moon
Waxing – more of the lit half of the Moon can be seen each night
Waxing Crescent – thin slice of the moon
First Quarter – half of the lit side is visible
Waxing Gibbous – more than ¼ of the Moon is visible
Full Moon – all of the Moon’s surface facing the Earth reflects light 13

14. Waning Phases of the Moon
Waning – less of the moon is visible each night
Waning Gibbous – just after the full moon
Third-Quarter – only half of the lit side of the Moon is visible
Waning Crescent - just before there is a new moon

15. Lunar Cycle

16. Eclipse

17. Solar Eclipse
A solar eclipse occurs when the Moon moves directly between the Sun and Earth and casts its shadow over part of the Earth
The eclipse may be a total or partial eclipse
Umbra – the darkest part of the Moon’s shadow
Penumbra – the lighter area around the umbra

18. Lunar Eclipse
Lunar Eclipse occurs when the Moon moves into the Earth’s penumbra and then enters into the umbra 18

19. The Earth’s Interior
The Kola Superdeep Borehole is an abandoned Cold War attempt by the Soviets to drill to the center of the Earth. The hole was drilled between 1970 and 1994, is 9 inches wide and reaches a depth of approximately 7.5 miles (40,230 feet) below the Earth’s surface.
Scientists are still analyzing the information they obtained while drillilng
Geologists use seismic (earthquake) waves to study the interior of the Earth.
Seismic waves travel at different speeds when the material they are moving through changes

20. Scientists study meteorites to learn about the Earth’s interior
Meteorites were formed in the early solar system.
Some meteorites are made up of iron and nickel which is what the core of the Earth is believed to be made up of
Map showing major impact basins

21. Earth’s Spheres All of the Earth’s layers interact, so the Earth’s
Earth’s Spheres All of the Earth’s layers interact, so the Earth’s surface is constantly changing
Atmosphere –thin layer of air
Hydrosphere – all the water on Earth
Biosphere – all living things on Earth
Lithosphere – solid part of the Earth

22. Layers of The Earth based on chemical composition
Crust – thin brittle layer of Earth
Mantle
Core

23. Fun Facts About the Crust
The crust is made up of 30 slow moving rocks
The moving plates are from 5 to 25 miles (8 to 40 kilometers) thick

24. Crust – 2 types Oceanic Crust
Made of basalt lava that flows onto the seafloor
Between 3-8 miles thick

25. Continental Crust Average thickness – 22 miles
Made of many different types of rocks
Less dense than oceanic crust

26. Mantle Trivia
The mantle is approximately 1800 miles (2880 kilometers) thick
The temperature of the mantle is between 1600 degrees and 8000 degrees Fahrenheit (871-4,426° C

27. Earth’s Mantle Hot, solid rock
The mantle is made mostly of the rock peridotite – a rock high in magnesium and iron

28. More on the Mantle
Heat flows through the mantle through the process of convection

29. Core Trivia
The outer core is a liquid made of melted iron and nickel. It is 1,400 miles (2,240 km) thick and reaches a temperature of 11,000°F (6087°C)
The inner core is solid iron and nickel and is 800 miles across (1280 km) and has a temperature over °F (7,200°C)

30. The Earth’s Core
Density calculations show that Earth’s core is metal
Seismic waves show that the inner core is a solid and the outer core is a liquid
Metallic meteorites and the magnetic field are also clues about the makeup of the core