1. Formation of the Solar System Chapter 3

2. A Solar System is Born Section 1 Vocabulary Nebula Solar Nebula

3. The Solar Nebula Clouds-Nebula Mixtures of mainly gas (helium and hydrogen) and dust made of elements such as carbon and iron Can be seen when nearby stars illuminate GRAVITY AND PRESSURE

4. Gravity Pulls Matter Together Made of matter Held together by the force of gravity A lot of space between the particles ◦ Less dense than air ◦ Gravitational attraction=weak  Strong enough to keep from drifting

5. Pressure Pushes Matter Apart Relationship between temperature and pressure Temperature-measure of the average kinetic energy of the particles in an object ◦ Energy of motion Little kinetic energy- move slowly and temp. of cloud is low A lot of kinetic energy- move fast and temp. of cloud is high Sometimes crash into each other In a nebula, outward pressure balances the inward gravitational pull and keeps the cloud from collapsing

6. Upsetting the Balance Gravity and Pressure ◦ Upset if two nebulas collide or nearby star explodes Compress small regions of a nebula called globules ◦ Gas clouds ◦ Become so dense they contract under their own gravity When it collapses inward the temp. increases and the stars can form Solar Nebula

7. How the Solar System Formed Collapse Took 10 million years for the solar system to form Denser and the attraction between the gas and dust particles increased Center of the cloud became very hot and dense Began to rotate slowly around the center Helped balance the pull of gravity Flattened into a rotating disk All planets

8. From Planetesimals to Planets Circled the center of the solar nebula ◦ Some collided ◦ Stuck together to form golf- sized bodies Drifted into the solar nebula ◦ Made them grow bigger Largest of the bodies are called planetesimals ◦ Small planets Some are part of the cores of current planets Some collided to form craters

9. Gas Giant or Rocky Planet? Largest formed near the outside of the rotating solar disk ◦ Hydrogen and Helium Far enough to attract nebula gases Grew to huge sizes and became gas giants Closer to the center temp. were to hot for gases to remain ◦ inner planets ◦ Rocky material

10. The Birth of a Star As they were forming other matter was traveling to the center Nuclear fusion Released huge amounts of energy and created enough outward pressure to balance the inward pull of gravity Sun was born

11. The Sun: Our Very Own Star Section 2 Vocabulary ◦ Nuclear Fusion ◦ Sunspot

12. The Structure of the Sun Not a solid surface Looking at the sun you seeing the outer atmosphere Made of many layers

13. Energy Production in the Sun Shining on Earth for about 4.6 billion years Sun burned fuel to generate its energy ◦ Amount of energy released by burning would not be enough to power the sun ◦ It would only last 10,000 years.

14. Burning or Shrinking? Burning would not last Started thinking that gravity was causing the sun to shrink slowly ◦ Would release enough energy to heat the sun ◦ Not enough power ◦ Would only last 45 million years ◦ Fossils-65 million years More powerful than gravity

15. Nuclear Fusion Beginning of 20 th century-Einstein showed that matter and energy are interchangable E=MC 2 Tiny amounts of matter can produce a huge amount of energy Nuclear Fusion-four hydrogen can nuclei can fuse to form a single nucleus of helium ◦ Energy is produced ◦ Sun gets its energy

16. Fusion in the Sun During normal conditions ◦ Never get close enough to combine ◦ Positively charged In the sun ◦ Temperature and pressure are very high ◦ Have enough energy to overcome the repulsive force ◦ Hydrogen fuses into helium

17. Fusion in the Sun The energy produced in the center ◦ Takes millions of years to reach the sun’s surface Radiative Zone- the energy passes from the core through a very dense region ◦ So crowed that the light and energy are blocked and sent in different directions Convective Zone-gases circulate ◦ Gases carry the energy up Photosphere- visible surface of the sun

18. Solar Activity Ever-Changing Place Thermal energy moves from the sun’s interior by the circulation of gases in the convective zone. Movement of energy- photosphere will boil and churn Circulation+Sun’s rotation= magnetic field

19. Sunspots Magnetic Field slows down activity in the convective zone ◦ Causes spots to be cooler ◦ Dark spots Sunspots ◦ Different size and shape ◦ 11 year cycle ◦ Peak intensity then decreases

20. Climate Confusion Sunspots can affect earth Period of low sunspot activity- low temperatures in Europa ◦ Little Ice Age More research is needed

21. Solar Flares Magnetic Fields can also cause solar flares Regions of extremely high temperature and brightness that develop on the sun’s surface Huge streams of electricity charged particles into the solar system ◦ Sunspots ◦ Interrupt radio communications

22. The Earth Takes Shape Section 3 Vocabulary ◦ Crust ◦ Mantle ◦ Core

23. Formation of the Solid Earth Third planet Mostly rock ¾ water Protective atmosphere ◦ Nitrogen ◦ oxygen Planetesimals collided and combined First 10 million years

24. The Effects of Gravity Small-irregular shape Planet gains more matter-gravity increases 350 km-gravity becomes greater than the strength of the rock Rock crushed by gravity and planet rounded

25. The Effect of Heat Changing shape-heating up Collisions of planetesimals- energy of motion heated the planet ◦ Radioactive material Certain size- temperature rose faster than the interior could cool and rocky material melted Still cooling ◦ Volcanoes, earthquakes, and hot springs ◦ Helped form layers

26. How the Earth’s Layers Formed Oil and vinegar Rock melted ◦ Denser materials sank (nickel and iron) and formed the core ◦ Less dense materials floated to the surface and formed the crust

27. How the Earth’s Layers Formed Crust- the thin outermost layer of the Earth ◦ 5-100 km think ◦ Low densities-oxygen silicon and aluminum Mantle-layer beneath the crust ◦ Extends 2,900 km