Which Renaissance scientist explained how planets move around the Sun?

During the Renaissance period, science began to move away from superstition and rely on careful observation and mathematics. Among the great thinkers of this era was Johannes Kepler (1571–1630), a German astronomer and mathematician who fundamentally changed how we understand the solar system.

Kepler built upon the ideas of Nicolaus Copernicus, who had earlier proposed that the Sun is at the center of the solar system. While Copernicus described circular orbits, Kepler discovered that the paths of the planets are not perfect circles but ellipses. This insight came from years of analyzing the precise observations of Tycho Brahe, a Danish astronomer with whom Kepler had worked.

Kepler formulated his famous Three Laws of Planetary Motion:

1. 
   

   Law of Elliptical Orbits: Every planet moves around the Sun in an ellipse, with the Sun at one focus.

   
   


2. 
   

   Law of Equal Areas: A line joining a planet and the Sun sweeps out equal areas in equal intervals of time, meaning planets move faster when closer to the Sun.

   
   


3. 
   

   Law of Harmonic Motion: The square of a planet’s orbital period is proportional to the cube of its average distance from the Sun.

   
   

These laws provided the first accurate mathematical description of planetary motion, explaining not only how planets move but also why their speeds vary. Kepler’s discoveries later enabled Isaac Newton to develop the law of universal gravitation, which gave the physical cause behind these motions.

Let’s review the options:

• 
  

  A) Johannes Kepler – ✅ Correct. Explained planetary motion using mathematical laws.

  
  


• 
  

  B) François Rabelais – A French writer, not a scientist.

  
  


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  C) Francis Bacon – Developed scientific reasoning but not planetary theory.

  
  


• 
  

  D) Johannes Gutenberg – Invented the printing press.

  
  

Thus, Johannes Kepler was the Renaissance scientist who scientifically explained how planets move around the Sun.

✅ Correct Answer: A) Johannes Kepler