1. Gravity: The force of attraction between the planet and the star it orbits (like the Sun for Earth). This force pulls the planet towards the star, constantly trying to make it fall inwards.
2. Inertia: The tendency of the planet to continue moving in a straight line. This force keeps the planet from falling directly into the star.
These two forces are in a delicate balance. Gravity pulls the planet towards the star, but inertia keeps it moving forward, resulting in a curved path, which is the orbit.
