Science at key stage 3 (Year 9)
Unit 9J: Gravity and space
Section 7: b. What keeps the planets and satellites in orbit?
|
|
Objectives |
| Children should learn: |
- that the Moon is a natural satellite of the Earth, whose orbit is maintained by the Earth's gravitational pull
|
Activities |
|
Outcomes |
|
Children: |
- Relate the orbit of the Moon round the Earth to that of the planets round the Sun. Explain that since the Moon is so close to the Earth, its orbit is influenced by the Earth's gravity rather than that of the Sun.
- Help pupils to visualise how an asteroid could be captured into an orbit by the gravitational field of a planet,
eg using a software simulation.
|
|
- state that the Moon is a natural satellite of the Earth, kept in orbit by the Earth's gravitational pull
|
|
Points to note |
- Pupils need to recognise that the Moon would travel in a straight line if it were not for the pull of the Earth's gravity. A software or video simulation would be useful to show this.
- Extension: the origin of the Moon in its current orbit has been of interest to astronomers for many years. Two opposing theories are:
- gravitational capture of an asteroid by the Earth
- an interplanetary collision during the early formation of the Earth, which threw off a ball of hot gases that have since coalesced to become the Moon
Pupils could find out about these two theories. Recent evidence supports the latter proposal.
|
|
|
This unit is divided into sections. Each section contains a sequence of
activities with related objectives and outcomes. You can view this unit by
moving through the sections or print/download the whole unit.
|
|
|
