Science at key stage 3    (Year 9)

• state that a ball dropped anywhere on the Earth will fall towards the centre of the planet, due to the attractive gravitational force between masses
• use the idea of gravity to explain a range of observations both familiar and novel

• use information provided to determine the mass and weight of objects on the Moon and other planets
• describe the implications of this for visitors to those places
• calculate and describe variation in weight

• show, eg by a force diagram, that a rocket needs a large upward force to rise against gravity
• describe, eg using annotations, that the gravitational force decreases as the rocket gets further from the Earth
• describe some of the landmarks of human exploration of space, eg Yuri Gagarin, Valentina Tereshkova, Neil Armstrong, Helen Sharman

• describe how the effects of gravity change during a voyage to the Moon and relate this to mass and weight of astronauts

• describe an early model of the solar system and how it differs from our present model
• argue a point of view in defence of a model of the solar system, providing evidence for their position
• use more formal language in their summary, eg passive verbs, third person

• extract relevant information from a video
• explain that it is the Sun's gravitational force that keeps planets in orbit

• state that the Moon is a natural satellite of the Earth, kept in orbit by the Earth's gravitational pull

• describe some uses of artificial satellites, eg to assist weather forecasting, TV transmissions
• explain why some satellites need to be in geostationary orbits
• describe how satellite probes provide information about the solar system and how this information is used

• produce key points related to mass and weight, the solar system, satellites