Kepler (1571 - 1630) announced his three famous laws of planetary motion in 1609:
Each planet or comet moves in an elliptical orbit, with the sun at one focus of the ellipse.
A line from the sun to a given planet sweeps out equal areas in equal time.
The periods of the planets are proportional to the 3/2 power of the major axis length of their orbits.
This animation illustrates the first two laws.
Click on to stop the animation.
Learning goals
To illustrate Kepler's laws.
Pedagogical scenario inspired by the 2014 Rosetta Mission downloadable here.
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The German astronomer Johannes Kepler (1571 – 1630) formulated the laws that govern the movement of two bodies subject only to their own mutual attraction. He arrived at these laws empirically,…