Where and how to look for aliens? The idea of extraterrestrial life fascinated humanity long before the exploration of outer space began. John Willis, astronomer and popularizer of science, gives five of the most realistic scenarios for searching for alien living beings in our Galaxy. Describing the latest advances in space exploration—finds from the Kepler space telescope, the Curiosity rover's exploration of Mars, the New Horizons flyby of Pluto, and many others—Willis empowers readers to choose their own means of discovering extraterrestrial life. He invites us to reflect on its existence under the Martian ice, on Jupiter's moon Europa and Saturn's moons Enceladus and Titan, and the author views the current conditions on Titan through the prism of our own planet's distant past. Willis looks beyond the solar system, discussing the chances of finding a “second Earth” among the billions of exoplanets likely to exist in our Galaxy, and also listens into deep space in hopes of hearing alien radio signals.