This book aims at providing a brief but broad overview of biosignatures. The topics addressed range from prebiotic signatures in extraterrestrial materials to the signatures characterising extant life as well as fossilised life, biosignatures related to space, and space flight instrumentation to detect biosignatures either in situ or from orbit. The book ends with philosophical reflections on the implications of life elsewhere. In the 15 chapters written by an interdisciplinary team of experts, it provides both detailed explanations on the nature of biosignatures as well as useful case studies showing how they are used and identified in ancient rocks, for example. One case study addresses the controversial finding of traces of fossil life in a meteorite from Mars. The book will be of interest not only to astrobiologists but also to terrestrial paleontologists as well as any reader interested in the prospects of finding a second example of life on another planet.

A rigorous and scientific analysis of the myriad possibilities of life beyond our planet. ÒAre we alone in the universe?Ó This tantalizing question has captivated humanity over millennia, but seldom has it been approached rigorously. Today the search for signatures of extraterrestrial life and intelligence has become a rapidly advancing scientific endeavor. Missions to Mars, Europa, and Titan seek evidence of life. Laboratory experiments have made great strides in creating synthetic life, deepening our understanding of conditions that give rise to living entities. And on the horizon are sophisticated telescopes to detect and characterize exoplanets most likely to harbor life. Life in the Cosmos offers a thorough overview of the burgeoning field of astrobiology, including the salient methods and paradigms involved in the search for extraterrestrial life and intelligence. Manasvi Lingam and Abraham Loeb tackle three areas of interest in hunting for life Òout thereÓ: first, the pathways by which life originates and evolves; second, planetary and stellar factors that affect the habitability of worlds, with an eye on the biomarkers that may reveal the presence of microbial life; and finally, the detection of technological signals that could be indicative of intelligence. Drawing on empirical data from observations and experiments, as well as the latest theoretical and computational developments, the authors make a compelling scientific case for the search for life beyond what we can currently see. Meticulous and comprehensive, Life in the Cosmos is a master class from top researchers in astrobiology, suggesting that the answer to our age-old question is closer than ever before.

Three recent developments have greatly increased interest in the search for life on Mars. The first is new information about the Martian environment including evidence of a watery past and the possibility of atmospheric methane. The second is the possibility of microbial viability on Mars. Finally, the Vision for Space Exploration initiative included an explicit directive to search for the evidence of life on Mars. These scientific and political developments led NASA to request the NRC's assistance in formulating an up-to-date integrated astrobiology strategy for Mars exploration. Among other topics, this report presents a review of current knowledge about possible life on Mars; an astrobiological assessment of current Mars missions; a review of Mars-mission planetary protection; and findings and recommendations. The report notes that the greatest increase in understanding of Mars will come from the collection and return to Earth of a well-chosen suite of Martian surface materials.

Over the past twenty years, astronomers have identified hundreds of extrasolar planets--planets orbiting stars other than the sun. Recent research in this burgeoning field has made it possible to observe and measure the atmospheres of these exoplanets. This is the first textbook to describe the basic physical processes--including radiative transfer, molecular absorption, and chemical processes--common to all planetary atmospheres, as well as the transit, eclipse, and thermal phase variation observations that are unique to exoplanets. In each chapter, Sara Seager offers a conceptual introduction, examples that combine the relevant physics equations with real data, and exercises. Topics range from foundational knowledge, such as the origin of atmospheric composition and planetary spectra, to more advanced concepts, such as solutions to the radiative transfer equation, polarization, and molecular and condensate opacities. Since planets vary widely in their atmospheric properties, Seager emphasizes the major physical processes that govern all planetary atmospheres. Moving from first principles to cutting-edge research, Exoplanet Atmospheres is an ideal resource for students and researchers in astronomy and earth sciences, one that will help prepare them for the next generation of planetary science. The first textbook to describe exoplanet atmospheres Illustrates concepts using examples grounded in real data Provides a step-by-step guide to understanding the structure and emergent spectrum of a planetary atmosphere Includes exercises for students

From Fossils to Astrobiology reviews developments in paleontology and geobiology that relate to the rapidly-developing field of Astrobiology, the study of life in the Universe. Many traditional areas of scientific study, including astronomy, chemistry and planetary science, contribute to Astrobiology, but the study of the record of life on planet Earth is critical in guiding investigations in the rest of the cosmos. In this varied book, expert scientists from 15 countries present peer-reviewed, stimulating reviews of paleontological and astrobiological studies. The overviews of established and emerging techniques for studying modern and ancient microorganisms on Earth and beyond, will be valuable guides to evaluating biosignatures which could be found in the extraterrestrial surface or subsurface within the Solar System and beyond. This volume also provides discussion on the controversial reports of "nanobacteria" in the Martian meteorite ALH84001. It is a unique volume among Astrobiology monographs in focusing on fossil evidence from the geological record and will be valuable to students and researchers alike.

This book presents an overview of current views on the origin of life and its earliest evolution. Each chapter describes key processes, environments and transition on the long road from geochemistry and astrochemistry to biochemistry and finally to the ancestors of today ́s organisms. This book combines the bottom-up and the top-down approaches to life including the origin of key chemical and structural features of living cells and the nature of abiotic factors that shaped these features in primordial environments. The book provides an overview of the topic as well as its state of the art for graduate students and newcomers to the field. It also serves as a reference for researchers in origins of life on Earth and beyond.