It's the biggest question we've ever faced, one that has fascinated generations of humans: do aliens exist? If they did, what would they look like? How would they think? And- what would it mean for us if we found them? Featuring fifteen pieces by top scientists and experts in the field, Aliens covers every aspect of the subject. For anyone who has ever looked up into the starry sky and wondered: are we alone? Engaging, authoritative, and filled with scientific insights.