A line joining a planet and the Sun sweeps out equal areas during equal intervals of time.
If you are looking for the original 1609 text (titled Astronomia Nova ΑΙΤΙΟΛΟΓΗΤΟΣ seu physica coelestis ), several digital libraries offer high-resolution scans: astronomia nova pdf
Offers beautiful, high-resolution scans of the original 1609 edition. A line joining a planet and the Sun
Planets move in elliptical orbits with the Sun at one focus. Kepler utilized the incredibly precise observations of Tycho
Kepler utilized the incredibly precise observations of Tycho Brahe.
Because the work was published over 400 years ago, it is in the public domain. However, the quality and language of the PDF vary. 1. The Original Latin Versions
Astronomia Nova PDF: Accessing Kepler’s Masterpiece Johannes Kepler’s Astronomia Nova (New Astronomy), published in 1609, stands as one of the most significant pillars in the history of science. It is the work that dismantled nearly two millennia of circular orbits and introduced the laws of planetary motion that we still use today.