Last Reviewed and Updated on June 17, 2022
Why do the planets orbit the sun? The simple answer is because of the gravity of our Sun!
The planets in our solar system orbit the sun because of the gravitational pull that the sun has on them. This force is what keeps them in orbit and prevents them from flying off into space.
The sun’s gravity pulls the planets towards it
Everything that has mass has gravity, and all bodies with mass pull other bodies towards them with the gravitational pull.
You might also want to read these facts about gravity.
The greater the mass of the body, the greater the gravitational pull is. In our Solar system, the Sun holds 99.8% of all of the mass, which makes it the body with the strongest gravity. This is the reason why every planet in our solar system orbits the sun and not something else.
Now you may be wondering why do the planets orbit the sun and not just get pulled in by it?
The planets orbit in an elliptical path
Planets orbit around the Sun, the Sun’s gravity constantly pulling them but they don’t get pulled in. Why is that?
Planets have a velocity in which they move, and the direction of their movement is perpendicular (meaning at a 90° angle) to the gravitational pull of the Sun. To simplify it, this balances out the pull, negating its pulling effect.
The direction and speed of the movement of planets and the gravitational pull of the Sun are what make the planets orbit the Sun and are what keep them at their distance.
If there were no Sun, the planets would travel in a straight line. If planets had no velocity, they would be pulled in by the Sun.
The speed of the planets orbiting increases the closer they are to the sun
The speed of the planets orbiting the sun increases the closer they are to the sun.
This is because the force of gravity decreases with distance, so the planets further from the sun feel a weaker gravitational force from the sun. As a result, they do not need to move as fast in order to maintain their orbit.
Mercury, the closest planet to the Sun has an orbital velocity at the speed of 47.9 km/s, while Neptune only needs to maintain a velocity of 5.4 km/s to remain in orbit.