Planetary Movements

Revolution-
A revolution is an instance of revolving.

Rotation-
An action of revolving around an axis or a center.

Gravity-
A force that causes all objects to move towards each other.

Two factors that determine the gravitational attraction between 2 objects are mass and distance.
The greater the distance the less force of gravity. The mass the amount of matter in an object so if the mass of an object is bigger the gravitational pull is stronger.

The two factors that keep a planet in orbit is gravity and inertia. Inertia is the tendency of an object to resist a change of motion. So gravity pulls the planets towards the sun, the planets keep moving forward because of inertia.

Two factors that keep planets in orbit

Two factors that determine the gravity between two objects