SOLAR SYSTEM

Detailed explanation-1: -While Copernicus rightly observed that the planets revolve around the Sun, it was Kepler who correctly defined their orbits. At the age of 27, Kepler became the assistant of a wealthy astronomer, Tycho Brahe, who asked him to define the orbit of Mars.

Detailed explanation-2: -Nicolaus Copernicus was a Polish astronomer who put forth the theory that the Sun is at rest near the center of the Universe, and that the Earth, spinning on its axis once daily, revolves annually around the Sun. This is called the heliocentric, or Sun-centered, system.

Detailed explanation-3: -Kepler’s first law-sometimes referred to as the law of ellipses-explains that planets are orbiting the sun in a path described as an ellipse. An ellipse can easily be constructed using a pencil, two tacks, a string, a sheet of paper and a piece of cardboard.

Detailed explanation-4: -Kepler’s 3rd Law is sometimes called The Law of Periods: The square of the period of any planet is proportional to the cube of the semimajor axis of its orbit.