The dream of sending humans to Mars is closer than ever before. In fact, many scientists think that the first person to set foot on the Red Planet is alive today. But where should the first explorers visit when they get there?　　Horizon has gathered the world's leading experts on Mars and asked them: where would they go, if they got the chance - and what would they need to survive?　　Using incredible real images and data, Horizon brings these Martian landmarks to life, from vast plains to towering volcanoes and from deep valleys to hidden underground caverns. The programme will also show viewers where to land, where to live… and even where to hunt for traces of extra-terrestrial life.　　This is the ultimate traveller's guide to Mars.…