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KEPLER'S LAWS

OF PLANETARY MOTION




KEPLER’S FIRST LAW OF PLANETARY MOTION


The LAW OF ELLIPSES

The path of an object orbiting the Sun is shaped like an ellipse, with the center of the Sun located at one focus.

example: The path of Earth’s orbit is shaped like an ellipse, not a perfect circle. Also, the Sun is not located at the very center of Earth’s orbit. Instead, the Sun is located at one focus of Earth’s orbit.


KEPLER’S SECOND LAW OF PLANETARY MOTION

The LAW OF EQUAL AREAS

An imaginary line drawn from the center of the Sun to the center of an object orbiting the Sun will sweep out equal areas in equal intervals of time.

example: An imaginary line drawn from the Sun’s center to Earth’s center will sweep out the same amount of area in any given month.



KEPLER’S THIRD LAW OF PLANETARY MOTION

The LAW OF HARMONIES

The ratio of the squares (^2) of the orbital periods (P) of any two planets is equal to the ratio of the cubes (^3) of their average distances from the sun (D).

example: Pe^2 / Pj^2 = De^3 / Dj^3




Kepler Online
http://www.brookscole.com/astronomy_d/special_features/astrotutor/mod_sci.html
This page features a reading, animation, and review questions about Kepler's Laws of Planetary Motion. Read the article, view the animation, take the "Guided Tour" of the animation, then write answers to 10 of the 17 questions on the "Worksheet." Each question is worth 5 points, for a total of 50 points. For full credit, please write your answers in complete sentences. Due on Friday, 10/20/06.

http://en.wikipedia.org/wiki/Johannes_Kepler Wikipedia's entery on Johannes Kepler