That's one of Johannes Kepler's "Laws" of planetary motion.
Johannes Kepler proposed that these planets orbit the sun in ellipses, not circles. That is why we have Kepler's Law of Planetary Motion.
Johannes Kepler is credited with forming the mathematics of elliptical orbits.
Johannes Kepler
He created the laws of plaetary motion
Several astronomers wrote theories of planetary motion. Ptolemy's theories date to antiquity. Copernicus wrote his theories in the early 16th century. Kepler's theories were written in the early 17th century.
Johannes Kepler
Sir Issac Newton
Actually, it was the other way around. Johannes Kepler needed Tyco Brahe's detailed records of the paths of the planets in order to verify his theories regarding planetary motion. Tyco's observations were the most accurate at the time, so Kepler sought him out.
Johannes Kepler
No. Kepler discovered the laws using Tycho Brahe's data.
Johannes Kepler
Johann Kepler.
I'm pretty sure you're thinking of Johannes Kepler.
He wrote Commentariolus (never published) and On the Revolutions of the Celestial Spheres (most famous work).
Isaac Newton.
His laws of planetary motion.