What is the source of centripetal force that a planet requires to revolve around the Sun? On what factors does that force depend?

The source of the centripetal force that a planet requires to revolve around the Sun is the gravitational attraction between the Sun and the planet. This force is determined by the mass of the Sun and the planet and their distance apart. The larger the masses of the Sun and the planet, or the closer they are to each other, the greater the gravitational attraction and thus the centripetal force. Every time the planet moves in its orbit, the gravitational attraction between them changes, causing the planet to constantly re-orient itself as it revolves around the Sun. This change in orientation is what causes the centripetal force. Thus, the centripetal force of a planet depends on the mass of the Sun and the planet, as well as the distance between them.