The Solar System

What the syllabus asks of you

• Describe the Solar System as containing: 7 Know that planets, minor planets and comets (a) one star, the Sun (b) the eight named planets and know their order from the Sun have elliptical orbits, and recall that the Sun is not at the centre of the elliptical orbit, except when the orbit is approximately circular (c) minor planets that orbit the Sun, including dwarf planets such as Pluto and asteroids in the asteroid belt (d) moons, that orbit the planets (e) smaller Solar System bodies, including comets and natural satellites 8 Analyse and interpret planetary data about orbital distance, orbital duration, density, surface temperature and uniform gravitational field strength at the planet’s surface
• Know that, in comparison to each other, the four planets nearest the Sun are rocky and small and the four planets furthest from the Sun are gaseous and large, and explain this difference by referring to an accretion model for Solar System formation, to include: (a) the model’s dependence on gravity (b) the presence of many elements in interstellar clouds of gas and dust (c) the rotation of material in the cloud and the formation of an accretion disc continued Core Supplement
• Know that 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
• Calculate the time it takes light to travel a significant distance such as between objects in the Solar System
• Know that the Sun contains most of the mass of the Solar System and this explains why the planets orbit the Sun
• Know that the force that keeps an object 9 Know that the strength of the Sun’s gravitational in orbit around the Sun is the gravitational field decreases and that the orbital speeds of attraction of the Sun the planets decrease as the distance from the Sun increases 10 Know that an object in an elliptical orbit travels faster when closer to the Sun and explain this using the conservation of energy