Circular orbit facts for kids
In astronomy, a circular orbit refers to an object (such as a planet or a star) which orbits around a central body in a fixed, circular motion. This motion follows Kepler's Laws. A circular orbit occurs when the eccentricity of its orbit is equal to 0.
Objects with a circular orbit are uncommon. The Moon moves in an elliptical orbit around the Earth, and the planets move in an elliptical orbit around the Sun.
Other types of motion in astronomy include elliptical orbit, parabolic trajectory, and hyperbolic trajectory.
Images for kids

A circular orbit is depicted in the topleft quadrant of this diagram, where the gravitational potential well of the central mass shows potential energy, and the kinetic energy of the orbital speed is shown in red. The height of the kinetic energy remains constant throughout the constant speed circular orbit.