We've been fascinated by it for thousands of years. It was the target of a 20th century technological arms race that would put the first humans in space and on extra-terrestrial soil, sparking exponential advances in spaceflight. Man got there, then left, and hasn't been back for 45 years. But now private investors, Kickstarter funds and international space agencies are clamouring to return. For something we see in the sky most nights it still holds an air of mystique. The Moon. As the European Space Agency prepares to land on the lunar surface again this episode of Brainwaves looks at the fascinating relationship between earth and its moon, hearing from those who have orbited the moon and those who are planning to return to it to form a human colony.