1. Kepler’s Law Eric Angat teacher

2. http://hyperphysics.phy-astr.gsu.edu/hbase/kepler.html Orbit Eccentricity The eccentricity of an ellipse can be defined as the ratio of the distance between the foci to the major axis of the ellipse. The eccentricity is zero for a circle. Of the planetary orbits, only Pluto has a large eccentricity. All planets move in elliptical orbits, with the sun at one focus. This is Kepler’s 1 st law!

3. Kepler’s 2 nd Law states that planets sweep equal _______ in equal amount of __________. Areas Time The area of this Is equal to the area of this They just have different shapes.

4. Kepler’s Second Law http://astronomy.osu.edu/ planets cover equal amount of areas at equal amount of time. This is Kepler’s 2nd law!

5. http://hyperphysics.phy-astr.gsu.edu/hbase/kepler.html planets move orbit faster when they are closer to the Sun. This is Kepler’s 2nd law!

6. P is the orbital velocity ( amount of time for a complete revolution.) What is the equation for Kepler’s 3 rd Law? P 2 = a 3 a is the Astronomical Unit (AU).

7. 1. Kepler’s 3 rd Law can determine the _____________of a planet given its distance from the Sun. a.orbital velocity or orbital period b.length of a year c.length of a day d.degree of ellipse of the orbit orbital velocity

8. 2. The diagram below demonstrates Kepler’s _____ Law. a.1 st b.2 nd c.3 rd d.4 th 2 nd

9. 3. The diagram below demonstrates Kepler’s _____ Law. a.1 st b.2 nd c.3 rd d.4 th 1 st Elliptical orbit

10. Johannes Kepler, working with data painstakingly collected by Tycho Brahe without the aid of a telescope, developed three laws which described the motion of the planets across the sky. 1.The Law of Orbits: All planets move in elliptical orbits, with the sun at one focus. 2. The Law of Areas: A line that connects a planet to the sun sweeps out equal areas in equal times. 3. The Law of Periods: The square of the period of any planet is proportional to the cube of the semimajor axis of its orbit. Kepler's laws were derived for orbits around the sun, but they apply to satellite orbits as well.