WARM UP: Please take out your review sheet.

1. Objectives 10/30/2013 8th Grade Plese enter quietly and begin your warm-up. WARM UP: • Please take out your review sheet. • Please get a pair of scissors (located by the handout bin) and begin to cut out your Dominos. • Put your Dominos together Agenda: • DOMINO Review • District Assessment Review GOAL: • I will ask Mrs. O any questions I may have on the ASTRONOMY material. HWK: District Assessment tomorrow & Bring your Textbook tomorrow!!

2. Chapter 2 Stars Review

3. District Assessment Review Questions 1. Describe the contributions of ALL early astronomers. • Ptolemy- • Copernicus- • Brahe- • Kepler- • Galileo- • Newton- • Hubble- • Earth Centered • Sun Centered • Earth Centered, excellent data • Planets revolve around sun in elliptical orbits, laws of planetary motion. • 1st to use a telescope to view the moon and planets • Gravity depends on mass and distance • There are other galaxies in the universe

4. 2. Refracting Telescopes Reflecting Telescopes Compare Reflecting and Refracting Telescopes • loss of brightness • lens expensive • larger the lens, more magnification, but more “bubbles” • Larger mirrors • Better • Hubble Space Telescope

5. 3. District Assessment Review Questions List the types of EMS that astronomers use to study objects in space.

6. District Assessment Review Questions 4. Explain how constellations are used to organize the night sky. • Constellations are regions in the sky (just like the state of Pa is a region in the US). • These patterns can be used like a map and to help locate other objects in space. • Polaris (which is part of the little dipper) helps travelers determine which way is North.

7. POLARIS • How to locate the North star?? • Find the BIG dipper and use the “pointer “ stars

8. District Assessment Review Questions 5. Compare size and scale ofthe universe, and explain how red shift indicates that the universe is expanding. • Closer objects appear to move more than farther objects. • Light-years= distance light travels in a year (9.46 trillion km!!!). • Red Shift- object is moving away. • Most galaxies emit a red shift, this tells scientists that the universe is expanding.

9. District Assessment Review Questions 6. Describe how color indicates the temperature of a star. • Blue= Hottest stars • White • Yellow • Orange • Red= cooler stars

10. District Assessment Review Questions 7. Explain how a scientist can identify a star’s composition • Stars are made up of different elements (gases) • Different elements absorb different wavelengths • Stars atmosphere absorbs light instead= absorption spectrum. • Pattern of dark lines in absorption spectrum shows the elements in the stars atmosphere.

11. District Assessment Review Questions 8. Describe how scientists classify stars • Stars are classified by how hot they are. • Temperature differences Color differences • O B A F G K M

12. District Assessment Review Questions 9. Compare absolute and apparent magnitude • Absolute Magnitude- the stars actual brightness. • If all the stars were the same distance away and rank them. • Apparent Magnitude- the brightness of the star as seen from Earth

13. District Assessment Review Questions 10. Identify how astronomer’s measure distance from earth to stars • Astronomers use Light-years. • Parallax- stars apparent shift in position • Stars appear to be moving around polaris the Earth is rotating and polaris is located over the North Pole.

14. District Assessment Review Questions 11. Describe the difference between apparent and actual motion of stars • Apparent- Stars and sun appear to move in the sky • All the stars appear to rotate around polaris because our earth is rotating. • Actual- star’s actual motion is hard to see BUT all stars are moving in space.

15. District Assessment Review Questions 12. Describe the different types of stars • Main Sequence Stars- second and longest phase. Most stars fall within this trend. Converting Hydrogen to Helium. • Red Giants- third stage in life cycle of stars, used expands and cools. Atmosphere of star expands as core shrinks • White Dwarfs- final stage, small, hot, dim star that is the left over center of an old star.

16. District Assessment Review Questions 13. Explain how stars at different stages in their life cycle appear on the H-R Diagram

17. District Assessment Review Questions 14. Identify the types of galaxies • Irregular Galaxy- no apparent shape due to its close proximity to a larger spiral galaxy. • Elliptical Galaxy- “cucumber shape” Older stars are located here; very bright centers and little gas or dust • Spiral Galaxy- Has “arms” made of dust, gas and are the location of star “birth” and “death”. Milky way Galaxy= example

18. District Assessment Review Questions 15. Describe the contents and characteristics of galaxies • Nebulas- cloud of dust and gas • Globular Cluster- tight group of stars that looks like a ball (up to 1 million stars) • Open Cluster- group of stars that are close together relative to surrounding stars • Quasars- luminous object that generates energy at a high rate. Most distant object in the universe.

19. District Assessment Review Questions 16. Describe the Big Bang • Big Bang Theory= theory that states the universe began with an explosion over approximately 13.7 billion years ago. • The universe rapidly began to expand and continues to expand today.

20. District Assessment Review Questions 17. Describe how the solar system formed. • 1. Nebula collapsed • 2. nebula flattens and rotates and begins to become warmer near the center. • 3. Planetesimals (small planets) begin to form within the swirling disk • 4. As larger planetesimals grow they attract more dust and gas due to their increasing gravity. • 5. Smaller planetesimals collide with the larger ones, and planets begin to grow. • 6. A star is born and the remaining dust and gas is blown out of the new solar system.

21. District Assessment Review Questions 18. Describe the basic structure of the sun

22. District Assessment Review Questions 19. Describe how the sun generates heat • NUCLEAR FUSION!!!

23. District Assessment Review Questions 20. Draw: Neap Tide and Spring Tide • Draw the 2 instances when you will have Neap Tides • Draw the 2 instances when you will have Spring times

24. Spring Tides Spring tides are caused by the moon being in the full or new moon phase. Therefore, we get spring tides twice a month *What phase do you see on this slide? New moon = sun and moon in line

25. Spring Tides *What phase do you see on this slide? Full Moon 3. Because the sun and moon pull together, you get the highest high tides and the lowest low tides during spring tide.

26. Neap Tides 1. Neap tides are caused when the moon is in the firstor lastquarter phase. Why? *The Sun’s and the moon’s pull are opposing * What phase is illustrated on this slide? First Quarter

27. Neap Tides * What phase is illustrated on this slide? Last Quarter

28. District Assessment Review Questions 21. What makes the seasons? • Seasons are the result of the tilt of the Earth's axis. • Earth’s axis is tilted 23.5°. • This tilting is why we have SEASONS like fall, winter, spring, summer.

29. District Assessment Review Questions 22. When are the soltices (winter and summer) When are the equinoxes (spring and fall)

30. District Assessment Review Questions 23. Please draw and label the phases of the Moon

31. District Assessment Review Questions 24. Draw a lunar eclipse Draw a solar eclipse