6.1.2 The Solar System
- Syllabus
- 0625–2026–2027
- Topic
- 6.1.2
- Level
- —
6.1.2.1—Contents: (a) the Sun (one star) (b)
- Describe Solar System contents: (a) the Sun (one star) (b) eight named planets in order from the Sun (c) minor planets, including Pluto/dwarf planets and asteroid-belt asteroids (d) moons orbiting planets (e) smaller bodies, including comets and natural satellites
6.1.2.2—Four inner planets are small/rocky and
- Know the four inner planets are small/rocky and the four outer planets are large/gaseous; explain this with the accretion model: gravity, many elements in gas/dust clouds, rotating cloud material and accretion-disc formation
6.1.2.3—Strength of the gravitational field
- Know: the strength of the gravitational field (a) at the surface of a planet depends on the mass of the planet (b) around a planet decreases as the distance from the planet increases
6.1.2.4—Time it takes light to travel a
- Calculate the time it takes light to travel a significant distance such as between objects in the Solar System
6.1.2.5—Sun contains most of the mass of the
- Know: the Sun contains most of the mass of the Solar System and this explains why the planets orbit the Sun
6.1.2.6—Force that keeps an object in orbit
- Know: the force that keeps an object in orbit around the Sun is the gravitational attraction of the Sun
6.1.2.7—Planets, minor planets and comets have
- Know: planets, minor planets and comets have elliptical orbits, and recall that the Sun is not at the centre of the elliptical orbit, except when the orbit is approximately circular
6.1.2.8—Analyse and interpret planetary data
- Analyse and interpret planetary data about orbital distance, orbital duration, density, surface temperature and uniform gravitational field strength at the planet’s surface
6.1.2.9—Strength of the Sun’s gravitational
- Know: the strength of the Sun’s gravitational field decreases and that the orbital speeds of the planets decrease as the distance from the Sun increases
6.1.2.10—An object in an elliptical orbit
- Know: an object in an elliptical orbit travels faster when closer to the Sun and explain this using the conservation of energy
Objective notes
10 learning objectivesConceptIGCSE Physics