Given the universal interest in whether extraterrestrial life has developed or could eventually develop, it is vital that an examination of planetary habitability go beyond simple assumptions. This book has resulted from a workshop at the International Space Science Institute (ISSI) which brought together experts to discuss the multi-faceted problem of how the habitability of a planet co-evolves with the geology of the surface and interior, the atmosphere, and the magnetosphere.

Is the Earth the right model and the only universal key to understand habitability, the origin and maintenance of life? Are we able to detect life elsewhere in the universe by the existing techniques and by the upcoming space missions? This book tries to give answers by focusing on environmental properties, which are playing a major role in influencing planetary surfaces or the interior of planets and satellites. The book gives insights into the nature of planets or satellites and their potential to harbor life. Different scientific disciplines are searching for the clues to classify planetary bodies as a habitable object and what kind of instruments and what kind of space exploration missions are necessary to detect life. Results from model calculations, field studies and from laboratory studies in planetary simulation facilities will help to elucidate if some of the planets and satellites in our solar system as well as in extra-solar systems are potentially habitable for life.

Extreme Habitable Environments is a book authored with the intention of providing introductory material suitable for those interested in learning about exoplanets. The focal point of this book is to expose its readers to the excitement in identifying exoplanets and exploring the possibility of life on them. This book offers structured content enriched with graphics, flow charts, images and worked examples that make reading and learning a delight. This book further serves as a hands-on perspective of the solar system and exoplanets. The first two chapters give a thorough insight into the solar system replete with the dynamics of star and planet formation. Exoplanets are introduced in the third chapter. Remaining chapters deal with various aspects of exoplanets, in a phased manner. Every chapter starts with an inspirational quote by a renowned personality. Content for every chapter is written in a down-to-earth style to facilitate readers' understanding and appreciation of the fundamental concepts. While some topics are basically descriptive, others start with a simple concept and progressively become more rigorous and detailed. Every effort has been made to make each chapter as complete as possible with a view of inciting curiosity in the minds of the readers and motivating them towards additional knowledge acquisition. Numerical exercises are included at the end of relevant chapters to help readers develop independent thinking, logical analysis and deductive skills. It is hoped that this book will cater to the needs of students desirous of pursuing research and a career in the field of Exoplanets.

“The Early Evolution of the Atmospheres of Terrestrial Planets” presents the main processes participating in the atmospheric evolution of terrestrial planets. A group of experts in the different fields provide an update of our current knowledge on this topic. Several papers in this book discuss the key role of nitrogen in the atmospheric evolution of terrestrial planets. The earliest setting and evolution of planetary atmospheres of terrestrial planets is directly associated with accretion, chemical differentiation, outgassing, stochastic impacts, and extremely high energy fluxes from their host stars. This book provides an overview of the present knowledge of the initial atmospheric composition of the terrestrial planets. Additionally it includes some papers about the current exoplanet discoveries and provides additional clues to our understanding of Earth’s transition from a hot accretionary phase into a habitable world. All papers included were reviewed by experts in their respective fields. We are living in an epoch of important exoplanet discoveries, but current properties of these exoplanets do not match our scientific predictions using standard terrestrial planet models. This book deals with the main physio-chemical signatures and processes that could be useful to better understand the formation of rocky planets.

Over the past ten years, the discovery of extrasolar planets has opened a new field of astronomy, and this area of research is rapidly growing, from both the observational and theoretical point of view. The presence of many giant exoplanets in the close vicinity of their star shows that these newly discovered planetary systems are very different from the solar system. New theoretical models are being developed in order to understand their formation scenarios, and new observational methods are being implemented to increase the sensitivity of exoplanet detections. In the present book, the authors address the question of planetary systems from all aspects. Starting from the facts (the detection of more than 300 extraterrestrial planets), they first describe the various methods used for these discoveries and propose a synthetic analysis of their global properties. They then consider the observations of young stars and circumstellar disks and address the case of the solar system as a specific example, different from the newly discovered systems. Then the study of planetary systems and of exoplanets is presented from a more theoretical point of view. The book ends with an outlook to future astronomical projects, and a description of the search for life on exoplanets. This book addresses students and researchers who wish to better understand this newly expanding field of research.