Standard 1a

1. Standard 1a • Nebular theory of solar system • Cloud of gas and dust • Most gas pulled to center (Sun) • 4 small rocky planets • 4 gas giant planets collected own gases • Astronomical unit between Earth and Sun. Light year distance light travels in a year

2. Standard 1b • Evidence includes: • Earth and Moon rocks suggest 4.6 billion year age. • Planets revolve in same direction in a plane. • Solar wind blew away atmosphere of first 4 planets.

3. Standard 1c • Earth formed from solids and gases from solar system • Heavy solids sunk to center • Light gases moved to surface and most escaped into space • Atmosphere changed from volcanic gases to oxygen because of plant growth

4. Standard 1c • Early atmosphere blown away by solar wind. • Comets brought ice (water). • Volcanic eruptions created carbon dioxide, nitrogen, other gases. • Plants used these to grow and create oxygen through photosynthesis.

5. Standard 1d • Planets are much closer to Earth than stars are • We know this because planets move across the sky while stars don’t • Radar and Doppler effect measure distances to stars. • Parallax can determine relative distance.

6. Standard 1e and f • 1e—Sun is powered by fusion to form helium from hydrogen • 1f—Asteroids have changed the surface features of the planets as shown by Mercury, Mars and the Moon • Obviously, they have also hit the Earth • Why do they not show as well?

7. Standard 2a • Our solar system is on the outer edge of the Milky Way galaxy. • Milky Way is spiral. • Others are elliptical and irregular.

8. Standard 2b • Galaxies contain billions of stars and most of the visible mass in the universe • Galaxies exist in clusters and superclusters. • There is dark matter in the universe that does not give off light

9. Standard 2c • Fusion in large stars creates heavier elements. • Elements to iron form by combining nuclei in stars. • Heavier elements form in supernova explosions.

10. Standard 2d • Different stars have different life cycles • Small stars die out as brown dwarfs • Large stars supernova to form pulsars and black holes • Spectroscopes used to determine star properties by seeing what elements are present.

11. Standard 3a • Ocean ridge system is spreading center. • Trenches are subduction areas. • Magnetic patterns • Age patterns • Topography of sea floor • Matching shorelines • Climate evidence

12. Standard 4a • Most energy on the Earth is from Sun • Small amount of energy is deep in Earth from radioactive decay • This helps to drive plate motion • Most energy to warm Earth and allow life is due to the Sun

13. Standard 4b • Solar energy may be absorbed or reflected by the atmosphere or the surface of the Earth • What effect does cloud cover have on surface temperature? • What effect does snow cover have on surface temperatures?

14. Standard 4c • Atmospheric gases absorbs heat and help regulate surface temperature • Gases allow short wavelengths through but when long wavelengths reflect from surface, they hold this heat in • Greenhouse effect must occur, but too much will create to much heat and global warming

15. Standard 5a • More heat at equator causes air to rise • Air from poles flows in to replace it • This allows movement of heat from equator to poles and helps regulate Earth temperatures

16. Standard 5b • Coriolis effect creates motions in the air and ocean • Ocean water near equator is heated, rises and flow north and south carrying heat with it • Cold water sinks in colder areas and moves to ocean floor where it heads toward the equator again

17. Standard 5c • Normally, warm air rises and cools • Temperature inversions occur when cold air moves in from one direction and hot from another • This does not allow the cold air to heat up and rise, so it stagnates • Creates smog

18. Standard 5d • Movement of ocean water is caused by solar heating and Earth rotation • Warm water rises, cold water sinks • More salt produces higher density and sinking

19. Standard 5e • Rain forests occur near the equator due to rising air • Deserts occur at 300 north and south due to cooling and sinking air • Mid latitude cyclones occur at roughly 600 north and south due to rising air masses • Poles have sinking air

20. Standard 6a • Weather and climate depend on the amount of solar energy into and out of the atmosphere • Weather is short term effects • Climate is long term averages

21. Standard 6b • Latitude creates climate as mentioned before • High elevation can create cooler climates and rain shadows • Nearness to large bodies of water regulate temperatures • Ocean currents can create warm climates in cold areas

22. Standard 6c • Climate changes over time • There have been ice ages and times that were warmer than now • Volcanoes, asteroid impact, human impact can all affect climate over time

23. Standard 7a • Carbon cycle has many steps, but is basically animals breathe out carbon dioxide and plants use this carbon dioxide to produce oxygen • Carbon in oil and coal is released when burned which may lead to global warming

24. Standard 7b • Carbon exists in many forms and changes from one to another • Carbon dioxide moves from air to water and is used by animals to form shells • Animals die and shells fall to bottom of ocean forming rock • Many other steps

25. Standard 7c • Energy to drive carbon cycle comes for solar energy and energy from the Earth • Heat from Earth drives subduction which pulls ocean carbonates down and melts them and erupts carbon back into atmosphere • Solar energy allows photosynthesis to occur

26. Standard 8a • Air is made of 78% nitrogen and 21% oxygen • Air is more dense at surface due to gravity • Temperature based layers decrease in temperature as height increases • Ozone keeps stratosphere warm

27. Standard 8b • Early atmosphere was mostly volcanic gases such as carbon dioxide and sulfur dioxide • Plants turned the carbon dioxide into oxygen • Atmospheric composition changed over time

28. Standard 8c • Ozone layer absorbs harmful ultraviolet radiation and becomes warmer • This not only helps Earth hold in heat, but it protects life from radiation • Greenhouse gases destroy ozone and allow more UV rays through • This may increase rates of skin cancers