Stonehenge is one of Britain’s most iconic monuments: an ancient stone circle still shrouded in layers of speculation and folklore. A new exhibition at the British Museum looks at the human story behind the stones, and offers new insights into the beliefs, rituals and worldview of our Neolithic ancestors. The curator Neil Wilkin tells Adam Rutherford about one of the objects on show – the metal Nebra Sky Disc – which is the world’s oldest surviving map of the sky.

The palaeobiologist Thomas Halliday looks even further back in deep time to reveal the Earth as it used to exist. In his new book Otherlands: A World in the Making he uses the latest technology and fossil records to examine ancient landscapes – from the mammoth steppe in Ice Age Alaska to the lush rainforests of Eocene Antarctica, with its colonies of giant penguins. While these distinct ecosystems appeared stable for millions of years, their disappearance is a reminder of the both the fragility and tenacity of the natural world.

Change and survival are at the centre of the writer and ecologist, Rebecca Nesbit’s book, Tickets for the Ark. As the current rate of extinction starts to resemble the demise of the dinosaurs 65 million years ago, conservationists appear to be fighting a losing battle. Nesbit questions the motives behind what we fight to save, in an examination of what we should conserve and why.

Producer: Katy Hickman