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Kepler's laws
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English
+ of planetary motion
Etymology
For Johannes Kepler, German mathematician and astronomer.
Noun
p Kepler's law 1
en astronomy The three laws of planetary motion discovered by Kepler in the early 17th century, stating that (i) the orbit of a planet is an ellipse with the Sun at one of the two foci, (ii) a line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time, and (iii) the square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit. en Copernican Revolution
Related terms
en Kepler's equation
en eponyms