1. What do you notice about the Orbit of the Planet’s compared to the Comet’s?

2. Aim: Describe Kepler’s Three Laws of Planetary Motion (eccentricity)

3. + + Which lane will Finish First? Which lane has a shorter distance to travel?

4. First Law: The planets move in elliptical orbits with the Sun at one focus. Planet Sun Foci

5. What is an ellipse? An ellipse is a closed curve around two fixed points called foci. Eccentricity- measures how stretched out, NOT circular an orbit is. Eccentricity= d (distance btwn foci) L (length of Major axis)

6. Label the following: distance between foci (d) and the Length of Major axis (L) d Planet Sun Foci L E= 5.2cm = 0.419 12.4cm ++

7. Which planet has the roundest orbit? Which one is the most ellongated? Which planet moves fastest? Which one moves the slowest Which eccentricity is closest to Uranus?

8. Find the eccentricity of the following Distance between Foci = 8.7 cm Length of Major Axis 10.2 cm

9. Is this orbit more or less eccentric as compared to the Earth?

10. 1. Describe the relationship between eccentricity of an ellipse and the shape of a planet’s orbit 2. State the relationship between distance between foci and eccentricity of orbit.

12. Use the ESRTp.15 Solar System Data Chart to answer the following: Planet with the Least eccentric orbit- Planet with the Most eccentric orbit- Venus – 0.007 (Most nearly Circular) Mercury – 0.206 State the range for eccentricity? 0.000 – 1.000 Circle - Line

13. Second Law-Law of equal areas. A line from the Sun to any planet sweeps out equal areas in equal time. SUN

14. X-Y = 30 days A-B = 30 days A 1 =A 2 A X B Y A2A2 A1 1. A planet must travel a longer distance in its orbit from X-Y.

15. 2. For a planet to travel from X-Y and A-B in the same amount of time it must increase its velocity in orbit from X-Y. 3. It is winter in the Northern Hemisphere. The seasons are caused by the Earth’s tilt on axis. The Northern Hemisphere is tilted away from the Sun during our Winter (January). B A X Y Perihelion- Planet is closest to the Sun Aphelion- Planet is furthest from the Sun SUN

16. Appears BIGGER Closer Perihelion SMALLER Farther Aphelion

17. Elliptical Orbits Interactive Animation: http://www.windows2universe.org/physical _science/physics/mechanics/orbit/orbit_sh ape_interactive.html http://www.windows2universe.org/physical _science/physics/mechanics/orbit/orbit_sh ape_interactive.html

18. Solar System Fill in the data table using your ESRT

19. Name of PlanetDistance from SunPeriod of Revolution Mercury 57.9 88 days Venus 108.2 224.7 days Earth 149.6 365.26 days Mars 227.9 687 days Jupiter 778.3 11.86 days Saturn 1,427 29.46 days Uranus 2,869 84.0 years Neptune 4,496 164.8 years Third Law-The further a planet is from the Sun, the longer its period of revolution. 1. Explain how a planet’s distance from the Sun affects its period of Revolution.

20. Fill in the organizer below: SUN AC APHELIONPERIHELION Distance From the Sun Earth’s location on the diagram Season Apparent Diameter of the Sun Acceleration in Orbit Gravitational Force Kinetic Energy/Potential Energy