As a new wave of interplanetary exploration unfolds, a talented young planetary scientist charts our centuries-old obsession with Mars.

Mars - bewilderingly empty, coated in red dust - is an unlikely place to pin our hopes of finding life elsewhere. And yet, right now multiple spacecraft are circling, sweeping over Terra Sabaea, Syrtis Major, the dunes of Elysium and Mare Sirenum - on the brink, perhaps, of a discovery that would inspire humankind as much as any in our history.

With poetic precision and grace, Sarah Stewart Johnson traces the evocative history of our explorations of Mars. She interlaces her personal journey as a scientist with tales of other seekers - from Galileo to William Herschel to Carl Sagan - who have scoured this enigmatic planet for signs of life and transformed it in our understanding from a distant point of light into a complex world. Ultimately, she shows how its story is also a story about Earth: it is a foil, a mirror, a tell-tale reflection of our own anxieties and yearnings to find - if we're lucky - that we're not alone.