Gravitational forces pull objects towards large objects like planets, moons and stars.

An attraction is a force that acts to pull one object towards another.

An orbit is the movement of one object in a loop around another object.

Gravity

Science

In the Gravity in space unit, they will build on this knowledge to learn to how gravitational forces cause orbital motion and about stellar evolution and cosmology, including red-shift and the big bang. 

In primary science, pupils learnt about the cause of day and night, the movement of the Earth orbiting the Sun and the Moon orbiting the Earth, and about stars and planets we can see in the night sky.

Solar system and beyond

It stops acting when an object is falling.

Which of these statements about the gravitational force from one object acting on another is correct?

Earth's gravitational force acts towards the centre of the planet.

Earth's gravitational force on the person acts downwards.

The Moon's gravitational force pushes the person toward Earth's surface.

Other forces, such as magnetic forces, hold them in place.

Why does the person shown on the southern hemisphere of Earth not fall off?

Put these objects in order of increasing gravitational field strength, starting with the smallest. 

The gravitational force on the Moon's surface is much less than it is on Earth.

There is no gravity on the Moon's surface to pull the flag down.

There is a breeze on the Moon which is blowing the flag to the left.

On the Moon, gravitational forces are repulsive, not attractive.

The photo shows an astronaut on the Moon with a flag. Why does the flag not droop towards the surface of the Moon?

At the altitude that communications satellites orbit Earth.

At the mid-point between the Moon and Earth.

Where would you feel the strongest gravitational force of attraction from Earth?

A gravitational force acts between all object with mass.

A gravitational force can only attract metals and only repel non-metals. 

A gravitational force only exists between solid objects.

The gravitational force of a spinning planet causes it to become flat. 

Which of these statements about gravitational forces is correct?

What is the name of the force that pulls objects towards the ground?

In which direction will a ball move if you pick it up and then release it above the ground?

Which scientist is thought to have discovered the existence of gravity after seeing an apple fall from a tree in their garden?

Which planet has the strongest gravitational field?

A communications satellite orbiting Earth.

The Sun orbiting the centre of the Milky Way galaxy.

Put these pairs of orbiting objects in order of increasing gravitational force between them, starting with the smallest. 

Gravity

Lesson outcome