Aiming for Grade 4 LOs:

• Compare the orbits of planets, moons, and artificial satellites.
• Describe how, for an object to be moving in an orbit, there must be a gravitational force acting directed at the centre of the orbit.
• List some uses of artificial satellites.

Aiming for Grade 6 LOs:

• State that, for a greater radius of orbit, the object must travel at a slower speed and orbit in a longer period.
• Describe the forces acting on an object that cause it to travel in a circular path.
• Describe the different orbits of a variety of satellites.

Aiming for Grade 8 LOs:

• Explain why a centripetal force can change the velocity of an object without changing its speed.
• Explain why the force acting on an object travelling in a circle must be at right angles to the direction of motion and directed towards the centre of the circle.
• Explain why a geostationary satellite must be a specific distance from the centre of the Earth.