gravitational force

Gravitational force is the invisible pulling force between any two objects that have mass.

• Earth has a huge mass, so its gravity pulls you, a ball, rain, and even the atmosphere towards its centre.
• Gravity acts at a distance: Earth does not need to touch an object to pull it. That is why it is called a non-contact force.
• The farther an object is from Earth, the weaker Earth’s pull becomes. This is why astronauts in orbit feel almost weightless, even though Earth’s gravity is still pulling them.
• Your weight is the force with which Earth pulls you. Your mass stays the same on the Moon, but your weight would be much less because the Moon’s gravity is weaker.
• Gravity also keeps the Moon moving around Earth and planets moving around the Sun. Without it, these objects would travel off in straight lines through space.

Although gravity is the weakest of the common forces, it becomes very important when large objects such as planets, stars, and galaxies are involved.