Humankind has pondered the idea of life existing beyond our solar system for many generations. Recent discoveries of “earthlike” planets have re-energized these speculations. But what makes Earth perfect for life, and what does that mean for extraterrestrial life? Lucky Planet by David Waltham addresses these questions.
Water has been identified in the most uncanny of places – as vapors in the nebulae that roam our Milky Way Galaxy, as ices in the protoplanetary disks that surround many protostars, and as liquids below the icy crusts of the Jovian moons Europa, Ganymede, and Callisto. In 2005, the Cassini spacecraft imaged geysers of liquid water erupting from the surface of Saturn’s moon Enceladus. The liquid form of water is especially important to biotic processes, as it provides an essential solvent for making the sundry hookups and energy transfers that are necessary to life.