Named after the Roman god of war (Ares in Greek), probably because of its blood red colour, Mars is the fourth planet from the Sun in the Solar System. Possibly the next destination for astronauts to visit, several successful unmanned spacecraft have already landed on Mars, taking pictures and examining the planet's rocks and soil. The planet once had water flowing on it and has ice caps at its poles. If life ever existed anywhere other than on Earth, Mars may have been that place!