Newton created a hypothetical scenario as follows. A person climbed a very tall mountain and launched a projectile horizontally from the peak. The projectile follows a parabolic path (see the above discussion relating to projectile motion) before striking the ground. If another projectile were launched faster than the first, then it would travel further before striking the ground. If yet another projectile were launched fast enough, then it should be able to travel right around the Earth because, as it falls, the surface of the Earth curves away from it. The curve of the projectile’s motion would follow that of the earth’s surface and thus not hit it. This projectile would then be in a circular orbit at a fixed height above the earth’s surface. (For an analysis of the forces operating to establish this circular motion, see below.)
If a projectile is launched still faster, its orbit will stretch out into an elliptical shape. Even faster launch velocities result in the projectile following a parabolic or hyperbolic path away from the Earth, escaping it entirely.