Answer: Determining planetary laws of motion.
Explanation:
Johannes Kepler ,German mathematicians,astronomer, astrologer. In seventeenth century, he is best known for his Laws of planetary motions.
The Law Planetary Motion are :
- the planets moves in elliptical path with the sun at one focus.
- A line that connects planet to a sun sweeps out equal area in equal time
- The square of orbital period of the planet is proportional to the cube of semi major axis of its orbit.
