The present well-established study of planets orbiting stars other than our Sun, the exoplanets, was reviewed by the author in his earlier book Wandering Stars. This new and exciting field of study has expanded quickly, particularly due to technological advances in both Earth-based telescopes and, more recently, in the application of automatic space vehicles. Well over 300 exoplanets have now been catalogued, each of mass comparable to or greater than those of the major planets of the Solar System. Earth-sized bodies remain out of reach for the present. The data obtained so far show that the distribution of major planets in our Solar System is the exception rather than the rule, contrary to earlier expectations. A few exoplanet systems do, nevertheless, give the promise of broadly Solar System conditions with the possibility of Earth-like components in appropriate orbits. This immediately raises the age-old question of whether there can be life elsewhere in the Universe and whether this might involve advanced technologically-capable beings like ourselves. The topic is explored in this workbook. To gain a balanced perspective on these matters, the arguments are set against the broad panorama of the Universe on the one hand and on the evolution of life on Earth leading to Homo sapiens on the other. | Physics of the Universe by Mendel Sachs, Paperback | Indigo Chapters