Kepler's laws

noun

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.

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Meanings

nounKepler's laws pl (normally plural, singular Kepler's law)

singular Kepler's law

  1. pluralplural normallyastronomyThe 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.

Origin

For Johannes Kepler, German mathematician and astronomer.

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Cite this entry
APA

Kepler's laws. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/Kepler's%20laws

MLA

“Kepler's laws.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Kepler's%20laws. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “Kepler's laws,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/Kepler's%20laws.

Source: Kepler's laws on Wiktionary, CC BY-SA 4.0.