The history of science shows many close connections between physics and astronomy. It is well known that a number of physical laws evolved from a base of astronomical observations. For example, Kepler observed and, later Newton derived, the laws of gravitation while studying the motion of planets and their satellites. The existence of thermonuclear energy was solidly established when it explained the energy balance of the Sun and stars. The anomalous shift of Mercury’s perihelion showed us that Newton’s gravitational theory was incomplete; this observation helped lead Einstein to the more comprehensive theory of General Relativity
