SOLAR SYSTEM

Detailed explanation-1: -Kepler’s First Law: each planet’s orbit about the Sun is an ellipse. The Sun’s center is always located at one focus of the orbital ellipse. The Sun is at one focus. The planet follows the ellipse in its orbit, meaning that the planet to Sun distance is constantly changing as the planet goes around its orbit.

Detailed explanation-2: -Then in 1609, German astrono-mer Johannes Kepler proved that the actual shape of Mars’ orbit is an ellipse. It followed that all of the planets follow elliptical orbits around the Sun, with the Sun at one focus point.

Detailed explanation-3: -Kepler’s laws of planetary motion …be stated as follows: (1) All planets move about the Sun in elliptical orbits, having the Sun as one of the foci. (2) A radius vector joining any planet to the Sun sweeps out equal areas in equal lengths of time.

Detailed explanation-4: -For many years, he struggled to make Brahe’s observations of the motions of Mars match up with a circular orbit. Eventually, however, Kepler noticed that an imaginary line drawn from a planet to the Sun swept out an equal area of space in equal times, regardless of where the planet was in its orbit.

Detailed explanation-5: -Kepler’s first law means that planets move around the Sun in elliptical orbits. An ellipse is a shape that resembles a flattened circle. How much the circle is flattened is expressed by its eccentricity. The eccentricity is a number between 0 and 1.