The Sun
The Sun.
Gravity and Inertia keeps the earth in orbit
The sun's gravitational pull keeps the earth in orbit around it.
The force that keeps the moon in orbit around the Earth is gravity. Specifically, the gravitational pull between the Earth and the moon is what keeps the moon in its elliptical orbit.
the sun
gravity
earth's gravity
gravity and inertia combine to keep earth in orbit because the suns gravity keeps the earth in orbit and the inertia keeps the earth from going in a straight line.
The earth is six times more massive than the moon. That keeps the moon in orbit around it, just as the mass of the sun keeps the earth in orbit around it.
its called gravity
The gravitational force.
Planets are kept in their orbit by the suns gravity, yet their momentum keeps them from falling into the sun. (Thank goodness!) Planets orbit in the direction their star rotates, so in our solar system, all planets orbit in the direction of the star.