Kepler's law

American  

noun

Astronomy.

1. any one of three laws governing planetary motion: each planet revolves in an ellipse, with the sun at one focus; the line connecting a planet to the sun sweeps out equal areas in equal periods of time law of areas; or the square of the period of revolution of each planet is proportional to the cube of the semimajor axis of the planet's orbit harmonic law.

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Etymology

Origin of Kepler's law

After J. Kepler

Example Sentences

From Kepler’s law, the period and the separation allow us to calculate the sum of the stars’ masses.

From Textbooks • Oct. 13, 2016

The masses are found using Kepler’s law for those few pulsars that are members of binary star systems.

From Textbooks • Oct. 13, 2016

By Kepler’s law, the planet moves fastest in its orbit when closest to the Sun.

From Textbooks • Oct. 13, 2016

Newton proved Kepler’s law using his second law of motion and his law of universal gravitation.

From Textbooks • Mar. 30, 2016

In this way, by assuming Kepler's law, we deduce the cube of the periodic time by a simple proportion, and the resulting value of 224·7 days can then be obtained.

From The Story of the Heavens by Ball, Robert S. (Robert Stawell), Sir