Before Kepler published his laws after years and years of calculations, people believed that the Earth was the centre of the universe and all other planets and the sun revolved around it. This was driven by religious beliefs of God being the creator of the Earth hence it was the focal point of the universe. Building on the works of astronomer **Nicolaus Copernicus** he provided mathematical proofs to his claims.

**Who Was Kepler?**

Johannes Kepler was born with a few disabilities. He had crippled hand and became visually impaired after suffering from smallpox. But he went on to join the greats **Tycho **and **Newton **to introduce and describe planetary orbits. Kepler worked on Tycho’s data that he collected as an observer and derived mathematical proofs for the orbits in the Solar System. Though his laws still hold true it took a while to gain recognition. In fact, in his lifetime he had to make a living by creating horoscopes.

**The Three Laws**

**The Law OF Ellipses**

Kepler nearly took 8 years to solve the Martian problem that he claimed he could in 8 days. Astronomers had long struggled why Mars appears to move back across the night sky. Thus, came Kepler’s First Law which states that **the path of the planets about the sun is elliptical in shape, with the centre of the sun being located at one focus of the ellipse. **

**The Law Of Equal Areas**

**Kepler’s Second Law **states that **the line from the sun to a planet sweeps out equal areas in equal times. **In simple words it’s the distance from the sun keeps changes during an orbit. That is, the planets move faster around the around the orbit when they are close to the sun and slow down when they are away from it. The state is just to quantify this motion.

**The Law Of Harmonies**

This law deals with the comparison between two orbits. He observed that planets that are farther away from the sun have larger orbits and hence take longer to complete a revolution even if they moved at same speeds. But he observed that also move at a lower rate of speed. To be exact he stated that **the square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of the orbit.**

The most fascinating part of these 3 laws is that it not only holds true for our solar system but wherever one body moves with respect to another’s gravitational force. Isn’t is fascinating? Can you think of where else these laws apply.