Kepler's laws

British  

plural noun

1. three laws of planetary motion published by Johannes Kepler between 1609 and 1619. The first states that the orbit of a planet describes an ellipse with the sun at one focus. The second states that, during one orbit, the straight line joining the sun and a planet sweeps out equal areas in equal times. The third states that the squares of the periods of any two planets are proportional to the cubes of their orbital major axes

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Example Sentences

We have seen that Kepler’s laws, which do not take into account the gravitational effects of the other planets on an orbit, really work quite well.

From Textbooks • Oct. 13, 2016

But we can measure the distance to many other solar system objects and use Kepler’s laws to give us the distance to the Sun.

From Textbooks • Oct. 13, 2016

From the observed motion and the period of the “wiggle,” they could deduce the mass of Jupiter and its distance using Kepler’s laws.

From Textbooks • Oct. 13, 2016

Although only 1.5 kilometers in diameter, smaller than many college campuses, Dactyl provides scientists with something otherwise beyond their reach—a measurement of the mass and density of Ida using Kepler’s laws.

From Textbooks • Oct. 13, 2016

Ptolemy gave the astrologers the information they needed, and Newton explained Kepler’s laws of planetary motion.

From "The Invention of Science" by David Wootton