Question

what was Isaac Newton's theory about the moon and earth?

Answer 1

The moon is only a projectile circling around the Earth under the attraction of Gravity. Newton called this force "gravity" and determined that gravitational forces exist between all objects. Using the idea of Gravity, Newton was able to explain the astronomical observations of Kepler.The Moon orbits around the Earth. Since its size does not appear to change, its distance stays about the same, and hence its orbit must be close to a circle. To keep the Moon moving in that circle--rather than wandering off--the Earth must exert a pull on the Moon, and Newton named that pulling force gravity