Crossword Puzzle PLANETS 7Online version Activities about the reading. by Javier Lipuzcoa Lopez 1 Mercury is the closest _______ to the Sun. 2 3 A planet about the same size as the Earth. 4 The number of planets in our solar system. 5 It is at the centre of our solar system. 6 Water exists on the planet Mars in the form of _______ 7 What colour is Mars? 4 7 6 2 1 3 5