Dirk Schulze Makuch

It has been nearly 100 years since the Apollo moon landings, when Jack and Vladimir, two astronauts on a mission to Venus, discover a mysterious void related to indigenous life on the planet. Subsequently more voids are detected on Earth, Mars, Titan, and, quite ominously, inside a planetoid emerging from the Kuiper belt.

Are humans a galactic oddity, or will complex life with human abilities develop on planets with environments that remain habitable for long enough? In a clear, jargon-free style, two leading researchers in the burgeoning field of astrobiology critically examine the major evolutionary steps that led us from the distant origins of life to the technologically advanced species we are today.

It is very unlikely that little green humanoids are living on Mars. But what are the possible life forms that might exist in our Solar System and how might they have evolved?

Energy, chemistry, solvents, and habitats – the basic elements of living systems - define the opportunities and limitations for life on other worlds. This class-tested text examines each of these parameters in crucial depth and makes the argument that life forms we would recognize may be more common in our solar system than many assume. It also considers, however, exotic forms of life that would not have to rely on carbon as basic chemical element, solar energy as a main energy source, or water as primary solvent. Finally the question of detecting bio- and geosignature of such life forms is discussed, ranging from Earth environments to deep space.

It is very unlikely that little green humanoids are living on Mars. But what are the possible life forms that might exist in our Solar System and how might they have evolved?