1. UNIT 4 SPACE EXPLORATION

2. Chapter 10 – The Universe Text page 350 ASTRONOMY – branch of physics which studies celestial bodies and the universe Any natural object out in space

3. Section 10.1 : Observing the Stars page 352 STAR – celestial body of hot gas with a nuclear core and makes it’s own thermal energy Star configurations seen from earth were often interpreted as different forms called constellations.

4. Constellations page 354 IAU (International Astronomical Union) lists 88 constellations Although stars appear close together they are actually very far apart Star Chart with current visible sky

5. 3 Common Must Know Constellations – Use your star chart to find them!

6. 1. Ursa Major – The Greater Bear Contains the asterism the big dipper Smaller groups of stars within constellations

8. 2. Ursa Minor – The Lesser Bear

10. 3. Orion – The Hunter

11. Find the Constellations

12. Start chart to Explore Tonight’s Sky

13. Section 10.2 : Early Models of the Universepage 352 ARISTOTLE 383-322 B.C.E geocentric universe with Earth at the center and the sun, moon and planets revolving around it reasoning based on the fact that the same pattern of stars could always be seen

14. Geocentric Model

15. PTOLEMY 83-168 B.C.E. realized that for Mars, the retrograde motion was not explained an apparent switch in the motion of a celestial body from East to West or vice versa as viewed from Earth

16. new model with each planet attached to a sphere with its center at earth but revolving around an epicycle (a point on its orbit) as it travelled around Earth used an astrolabe

17. COPERNICUS 1473-1543 Heliocentric view (with the sun the center of the universe) Earth rotate about its axis daily

18. Heliocentric Model

19. GALILEO 1564 - 1642 first to use a refracting telescope (had a magnification of 20x, less than most modern backyard telescopes) noticed phases of Venus which supported the heliocentric model

20. KEPLER 1571-1630 enlisted the help of Tycho Brahe and discovered planets actually orbited the sun in elliptical orbits

21. NEWTON 1643-1727 predicted that gravity explains why the planets stay in orbit, the LARGER the size the greater the force of gravity, smaller objects revolve around LARGER use Newtonian laws to determine how to send satellites in orbit, Invented a reflecting telescope

22. The Universe Beyond the Big Bang (time 10:30-35:00)The Universe Beyond the Big Bang