Name_____________________________________________________ Lecture and Study Guide 1. What is the definition of the Universe? 2. What are galaxies and how many are there? 3. What is a light year and what is the speed of light? 4. What are the 2 main components of stars? 5. How many stars are in a galaxy? 6. How do stars produce energy? 7. What is a solar system and what are the objects it contains? 8. What is the name of our galaxy? 9. What is the definition of a planet? 10. Why are planets round? 11. Give 3 examples of satellites. 12. What did Copernicus discover? 13. What was the relationship between Brahe and Kepler? 14. Explain Kepler’s first law. 15. Explain Kepler’s second law. 16. What is the main point of Kepler’s third law? 17. How does the moon stay in an orbit about the Earth? 18. What is the difference between rotation and revolution? 19. What is a leap year and why does it occur? 20. Why do we have seasons? 21. Explain precession. 22. Explain nutation. How does this affect the seasons? 23. Explain barycenter. 24. What causes tides? 25. Is the moon or Sun responsible for the tides? 26. Why is there a bulge at the equator of the Earth?