Travel Around the Planet br An astronaut who has circled the planet. and Down on the planet Mars. Circulation of the Planets on the Sun New calculations find that the closest planet to Earth is Mercury. New calculations find that the closest planet to Earth is Mercury. Illustration of planet Earth. Illustration of Saturn and its rings. There are eight planets in the solar system. The planets revolve around the sun which is the largest solar system. Any planet that moves or revolves around the sun in the motion of revolution or the movement of the planets. The motion of the revolution of each planet is different and in a regular time. They also have their own trajectory. So that the planets do not collide with each other. The planet closest to the sun has the fastest time of revolution.