Unit 6 The Earth And The Universe - Note

• The main constituents of the Solar System are the Sun and the planets.
• The sequence of planets starting from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
• The planets differ in size and distance from the Sun.
• The planets have very different conditions on their surfaces.
• The Sun is in the centre of the Solar System.
• The Sun is very big compared to the planets.
• All planets move round the Sun.
• The ratio of the size of the Moon to Earth and to the Sun is 1:4:400.
• The distance from Earth to the Sun is 400 times the distance from the Moon to Earth.
• Earth has water, air and a suitable temperature to support life.
• If Earth is too near to the Sun, it will be too hot to support life.
• If Earth is too far to the Sun, it will be too cold to support life.
• Earth is the only planet in the Solar System that has life on it.