1. Science Starter
Kepler’s 1st law states that planetary orbits are _________________ shapes?
Kepler’s 2nd law states that 2 equal intervals of time an imaginary line connecting a planet and the sun will sweep an equal amount of ___________?
Kepler’s third law states that the innermost planets orbit ______________________ than the outermost planets.
Rotation is the earth spinning on it’s _________________.
One trip around the ______________ is called a revolution.

2. Objective
SWBAT explain the Earth’s motion through space

3. Agenda
Science Starter
Review Last Class
Eccentricity
Worksheet

4. Homework
Worksheet

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

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

7. + + Which lane will Finish First?
Which lane has a shorter distance to travel?
Lane 1
Start/Finish
Lane 6

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

9. 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)

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

11. Which planet has the roundest orbit. Which one is the most ellongated
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?

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

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

14. 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.

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

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

18. 1. A planet must travel a longer distance in its orbit from X-Y .
X-Y = 30 days A-B = 30 days A1=A2 X B A1 A2 A Y
1. A planet must travel a longer distance in its orbit from X-Y .

19. Perihelion-
Planet is closest to the Sun
Aphelion- Planet is furthest from the Sun X B A Y
SUN
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).

20. Appears BIGGER Closer Perihelion
SMALLER Farther
Aphelion
Appears BIGGER Closer Perihelion

21. Elliptical Orbits Interactive Animation: http://www. windows2universe

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

23. Name of Planet
Distance from Sun
Period of Revolution
Mercury
57.9
88 days
Venus
108.2
224.7 days
Earth
149.6
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.

24. Exit Ticket
Reflect on what we’ve learned today by finishing the following sentences.
Today, I learned …
I was surprised to find …
I wonder what would happen if…
The important thing about …