The moon may be the closest planetary body to us, but we still have a lot to learn about it. For example, what is the water-cycle like on an airless body such as the moon? How much water can be found there, and could we one day utilise this water for space exploration? In this episode of the Big Questions Podcast, we chat to Dr Katherine Shirley, a planetary scientist at the University of Oxford who is also a member of the science team for NASA's Lunar Trailblazer mission. A hydroponic station on the moon? Maybe it's not just sci-fi fantasy...