Download Kepler*s laws of planetary motion

11/10/15
KEPLER’S LAWS OF PLANETARY
MOTION
Objective: I will summarize Kepler’s three laws of
planetary motion.
Early Models of the Solar System
• Geocentric model- developed by Aristotle ~2,000 years ago
• Earth centered, with the Sun, stars, and planets revolving
around Earth
• Ptolemy model- sought to better explain the geocentric
model
• Still had Earth as the center of the solar system
• Heliocentric model- developed by Copernicus
• Sun-centered solar system with planets revolving
around the Sun in the same direction
• Johannes Kepler- noticed a pattern in data of planetary
motion
• Developed 3 laws to explain the motion of orbiting
object
Kepler’s 1st Law- Law of Ellipses
• Each planet orbits the sun in a path called an ellipse,
not a circle
• Shape of the ellipse determined by two points, called
a focus
• Eccentricity- degree of elongation of an elliptical
orbit
• Circular e=0
Flattened ellipse e=1
• Perihelion- point of orbit closest to the sun
• Aphelion- point of orbit furthest away
Kepler’s 1st Law- Law of Ellipses
Kepler’s 2nd Law- Law of Equal Areas
• The area through which an objects
sweeps in a given period of time are equal
• Describes the speed objects travel at
different points in their orbit
• Therefore, objects travel fastest when
close to the sun, and slowest when far
away from the sun
Kepler’s 2nd Law- Law of Equal Areas
Kepler’s 3rd Law- Law of Periods
• Describes the relationship between the
average distance of a planet from the sun
and the planet’s orbital period
• Orbital period- time required for planet to
complete one orbit
• Helps astronomers find out how far away
planets are from the sun
Kepler’s 3rd Law- Law of Periods
Newton’s Law of Universal Attraction
• The force of gravity exists between any two
objects in the universe
• Newton's Law of Universal Gravitation- force
between two objects is directly proportional to the
product of their masses and inversely
proportional to the square of the distance
between them
• Bigger objects exert more gravity
• Objects that are farther apart exert less gravity on
each other than when they are close together
Kepler’s Laws Haiku (Output Activity)
• On your left-side page, you will create three (3) separate
Haiku poems.
• One poem each for:
• Kepler’s 1st Law
• Kepler’s 2nd Law
• Kepler’s 3rd Law
• Remember to include a title and color!
Haiku Output Activity