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Which book presented Johannes Kepler's first two laws of planetary motion?
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Johannes Kepler
Johannes Kepler, engraving by N. Dietz.
Johannes Kepler presented his first two laws of planetary motion in his 1609 book, Astronomia Nova (New Astronomy).
These two laws are:
* First Law: The paths of planets are ellipses with the Sun located at one focus.
* Second Law: A planet moves around the Sun at a variable speed such that a line connecting the planet to the Sun sweeps out equal areas in equal times.1
Kepler later announced his third law in his 1619 work, Harmonice Mundi (The Harmony of the World).1