1. Where are we going? New Quarter = New Unit EARTH AND SPACE SCIENCE!

2. What’s at the center? Today we’re talking about what is at the center of the solar system. Sometimes, people disagree. Today we’re talking about when ancient scientists disagreed – “what’s at the center?” – the sun or the earth?

3. Who cares? Have you ever watched the stars on a clear night and seen them as they seem to move across the sky? Why do they look like that?

4. Essential Question So what is at the center for our world? Question of the Day: What is at the center of our solar system and what scientists figured it out?

5. Geocentric System Ancient Greek astronomers (meaning they looked at the stars) believed in a (1) geocentric system. A geocentric system means that the (2) Earth is at the center of the solar system and all the planets (3) revolve around the Earth.

6. Geocentric System If you watch the stars at night, it looks like they’re moving across the sky. During the day, the sun appears to move across the sky. The ancient Greeks saw that and thought that the sun, moon and stars were moving while (4) the Earth stayed still.

7. Geocentric System Earth at the center

8. quick check for ROCKSTAR status How do Earth and the other planets move in the heliocentric system?

9. Copernicus Enter in the BEAUTIFUL Nicolaus (5) Copernicus who developed a new model for the motion of the planets

10. Copernicus Copernicus believed we live in a (6) heliocentric system Helios is Greek for sun

11. quick check for ROCKSTAR status What do you think a heliocentric system is?

12. Heliocentric System In a heliocentric system, Earth and the other planets (7) revolve around the sun.

13. Heliocentric System

14. quick check for ROCKSTAR status What is the difference between a heliocentric and geocentric system?

15. People disagreed with Copernicus because they did not want to think that the Earth was not at the center of the universe

16. In science, we need more EVIDENCE to convince someone! Enter in the BEAUTIFUL Galileo Galilei who gave us evidence

17. In science, we need more EVIDENCE to convince someone! (8) Galileo used the newly invented (9) telescope to make discoveries that supported the heliocentric model.

18. In science, we need more EVIDENCE to convince someone! Galileo used a telescope to see (10) four moons revolving around Jupiter. This proved that not everything in the sky revolves around Earth.

19. In science, we need more EVIDENCE to convince someone! Galileo also saw that Venus (11)goes through phases like Earth’s moon. Venus would not have phases if it circled around Earth.

20. quick check for ROCKSTAR status What is a geocentric system?

21. Quick check for ROCKSTAR status Which superstar scientist helped us figure out the RIGHT model for our solar system??

22. quick check for ROCKSTAR status What is a heliocentric system?

23. quick check for ROCKSTAR status How did Galileo’s observations of Jupiter and Venus support Copernicus’ model?

24. Quick check for ROCKSTAR Status Sooooo what object is in the center of our solar system??

25. quick check for ROCKSTAR status People often say that the sun rises in the east, crosses in the sky, and sets in the west. Is this literally true? Explain.

26. Quick Check for ROCKSTAR Status Make a prediction….if the world DID revolve around the Earth…would the sun and moon act the same way they do now??