1. Chapter 8
The Solar System

2. How was it formed The Nebular Theory
Started as nebula about 5 billion years ago
Composed of hydrogen and helium
Nearby supernova sent shock waves through galaxy
caused gases to be pulled inward
supplied new elements
Shrank to a spinning disk –10 billion kilometers across
Gravity heated center to protostar - the sun

3. How was it formed Other matter spun around the new sun
gathered into clumps- protoplanets
Near the sun the light weight gases boiled away
Mercury, Venus, Earth, Mars
In those far away the gases did not boil away
Jupiter, Saturn, Uranus, Neptune
the gas giants

4. How was it formed
Around the protoplanets smaller clumps formed moons or satellites.
Pluto is thought to be a moon of Neptune that broke away.
Asteroid belt- clumps of rocks between Mars and Jupiter
Jupiter’s gravity stopped a planet from forming
Oort Cloud- Near the edge clumps of matter- home of comets.

5. The Origin of the Moon Giant Impact Hypothesis
A very large body crashed into the Earth. Debris from the impact made a moon.

6. 4.6 byr ago -- Moon formed, possibly due to collision of Earth and a large, Mars-sized object.
If Earth already differentiated, most material expelled would be mantle material, not iron core

7. Rock at impact heated, losing volatile elements
Some debris falls back to Earth, some forms Moon.
Earth and Moon each pulled back into spherical shape by gravity.

8. Why Do We Think This? The moon has no iron
Earth’s iron had already concentrated in the core by the time of the impact
The iron core of the impactor melded with that of the Earth, leaving the moon with no iron of its own
The moon and Earth share isotopes of oxygen that are not found on other planets or objects far from Earth

9. Surface Features on the Moon
Two types of Surfaces
Highlands
More heavily cratered  surface is older.
Maria (“Seas”)
Less heavily cratered  surface is younger.

10. 2 Bulges from Gravitational Attraction & Centrifugal Force
What causes tides?
2 Bulges from Gravitational Attraction & Centrifugal Force

11. Gravitational Attraction
All masses are drawn to each other.
The moon because of its closeness to the Earth exerts a greater gravitational effect on the Earth than the Sun, despite the fact that the Sun is much more massive than the Moon.

12. Centrifugal Force unequal masses of Earth and Moon second tidal bulge
center of rotation lies beneath the Earth’s surface.
second tidal bulge
ocean shifts away from center of rotation
AWAY from center
can be observed in action on a passenger riding in a car. If the car swerves around a corner, the passenger's body pushes against the outer edge of the car

13. Special Features of the Planets
Mercury
Many Craters
no atmosphere
no erosion
Slow rotation makes it hot and cold

14. Venus Thick atmosphere of carbon dioxide Sulfuric acid clouds
Greenhouse effect
carbon dioxide traps heat.
Makes Venus hotter than Mercury
Retrograde rotation - rotates backward

15. Mars Red planet- covered by iron oxide (rust) Mons Olympus -
Largest volcano in the solar system
Two ice caps
north - water -never melts
south -carbon dioxide melts in summer

16. Two moons of Mars
Phobos
Deimos

17. Jupiter

18. Jupiter Largest of the gas giants Huge storms - red spot
Small solid core
Liquid metal layer makes a huge magnetic field
Magnetosphere
Gives off more heat than it receives from the sun
Thin ring

19. 16 moons
4 seen by Galileo helped change science

20. Saturn Similar to Jupiter Clouds, magnetosphere, gives off heat
Rotates in 10 hours - makes it bulge in the middle and flat at the poles
Low density- would float in water

21. Saturn
Many rings
complex system
made of water
weave in and out

22. Saturn
Many moons -
Titan- the largest is like the early Earth.

23. Uranus Twice as far from the sun as Saturn.
Covered with ocean of superheated water
Tilted on axis
Rings of methane ice
Many moons

24. Neptune Like Uranus Hydrogen and helium atmosphere
Surface of water and methane
Rings made of dust
Eight moons

25. Triton Large moon Thought to be captured Retrograde revolution
out of plane of Neptune’s rotation

26. Pluto Moon sized Made of methane Pink atmosphere on the sunny side
Moon Charon 1/2 the size of Pluto
Scientists think it is a moon broken away from Neptune
Orbit crosses Neptune
Orbit not in plane with other planets

27. The Sun An average star Over 1 million earth’s would fit inside
1/4 the density of the Earth
made of 4 layers

28. Corona- Outermost layer
Temp-1,700,000ºC
Few particles
Chromosphere-
middle of atmosphere
Temp-27,800ºC
1000’s of km thick

29. Photosphere-
Temp-6000ºC
550 km thick
Surface of the sun
Core-
1,000,000ºC
15,000,000ºC

30. Activity on the Sun Storms on the sun
Prominences- Loops or arches of gas that rise from the chromosphere
Solar Flares- Bright bursts of light, huge amounts of energy released
Sunspots- Dark areas on the suns surface
in the lower atmosphere
Motion shows the rotation of the sun
Interferes with radio

31. Meteorites Leave a crater where they hit the ground
Meteorite Crater in Arizona
Evidence of meteorites from the moon and from Mars

32. Comets Chunks of dust and gas from the Oort Cloud that orbit the sun
When it gets close to the sun it gets hotter
Some of the gas and dust form a cloud around the head called the coma
Solar wind pushes the gases away from the sun and make the tail
Tail is pushed by the solar wind
Tail always points way from the sun

33. Solar wind
Coma
Tail
Nucleus