They all move in a path that obeys the laws of motion and the force that controls their motion is the gravity. The inner planets orbit swiftly than the outer planets. Motion of Celestial Bodies in the Solar SystemĪll planets orbit in a counterclockwise direction. Newton further generalized the law by saying that not only the earth but all material bodies in the universe attract each other according to equation (1) with the same value of G. M = Mass of a larger body, separated by the square of the distance ‘r.’ G = Universal gravitational constant whose value = 6.673 x 1 0 -11 N m 2 /k g 2 He formulated an equation to showcase the force between the earth and the body, i.e., The acceleration of a body falling near the earth’s surface = 9.8 m s -2. This means all the objects in the universe fall freely under the influence of gravity such that the force acts towards the center of the earth. He stated that the laws of nature are the same for earthly and heavenly bodies. In the year 1665, an English mathematician, physicist, astronomer, and theologian named Isaac Newton studied the motion of the moon about the earth. This states that the square of the time period, T of the revolution of a planet is proportional to the cube power of the semi-major axis,r of the ellipse. Third Law: This law is also called the law of ellipses. Second Law: The radius vector, r from the sun to the planet traces equal area in equal intervals of time. They are:įirst Law: It states that all planets make an elliptical locus with the sun at a focus. Kepler formulated his important findings in his three laws of planetary motion. Movement of Celestial BodiesĪ thousand years after Aryabhata, the brilliant combination of Tycho Brahe and Johannes Kepler studied planetary motion in significant detail. He also gave a conclusion in his book Aryabhatiya that the earth revolves around its axis and moves in a circular orbit about the sun and that the moon moves in a circular orbit around the earth. The motion of celestial bodies such as the moon, the earth, other planets have been a subject of significant interest for a long time.Ī famous Indian astronomer and mathematician, Aryabhata did the in-depth study of these motions.Īfter that, he proposed a theory of the elliptical path of planets where he stated that all the planets remain stable, and as they come closer to the sun because of attraction, their speed increases proportionately.

The study of heavenly bodies