"You've probably heard about the existence of water on Mars. But what does this actually mean? Is there a slight chance of unknown life on mars that lived million or even a billion years ago? This kind of possibility has fuelled man's quest to visit the Red Planet. Man's attempts to reach Mars have pushed technological boundaries past their limit and raised the prospect of establishing human colonies beyond our own planet.
Horizon has explored how scientists believe the only way to truly understand Mars is to send people there. If and when we do, it will be the most challenging trip humanity has ever undertaken."