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.

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

Astrobiology not only investigates how early life took hold of our planet but also life on other planets – both in our Solar System and beyond – and their potential for habitability. The book take readers from the scars on planetary surfaces made by space rocks to the history of the Solar System narrated by those space rocks as well as exoplanets in other planetary systems. But the true question is how life arose here or elsewhere. Modern comparative genomics has revealed that Darwin was correct; a set of highly conserved genes and cellular functions indicate that all life is related by common ancestry. The Last Universal Common Ancestor or LUCA sits at the base of the Tree of Life. However, once that life took hold, it started to diversify and form complex microbial communities that are known as microbial mats and stromatolites. Due to their long evolutionary history and abundance on modern Earth, research on the biological, chemical and geological processes of stromatolite formation has provided important insights into the field of astrobiology. Many of these microbialite-containing ecosystems have been used as models for astrobiology, and NASA mission analogs including Shark Bay, Pavilion and Kelly Lakes. Modern microbialites represent natural laboratories to study primordial ecosystems and provide proxies for how life could evolve on other planets. However, few viral metagenomic studies (i.e., viromes) have been conducted in microbialites, which are not only an important part of the community but also mirror its biodiversity. This book focuses on particularly interesting sites such as Andean lake microbialites, a proxy of early life since they are characterized by very high UV light, while Alchichica and Bacalar lakes are characterized by high-salt and oligotrophic waters that nurture stromatolites. However, it is only the oasis of Cuatro Ciénegas Basin in México that stored past life in its marine sediments of the Sierra de San Marcos. This particular Sierra has a magmatic pouch that moves the deep aquifer to the surface in a cycle of sun drenched life and back to the depths of the magmatic life in an ancient cycle that now is broken by the overexploitation of the surface water as well as the deep aquifer in order to irrigate alfalfa in the desert. The anthropocene, the era of human folly, is killing this unique time machine and with it the memory of the planet.

Examines the origins of life on Earth and the search for extraterrestrial life, through an understanding of the factors that have allowed life to exist on this planet and the commonalities on others that may enable life elsewhere.

"This book: Provides extensive grounding in key issues of astrophysics, chemistry, biology and geophysics; over 150 images and illustrations; exercises for each chapter, ranging from straightforward calculation problems to more far-ranging research-oriented exercises; an online component for users that includes new exercises and a continually updated blog of late-breaking scientific news items, fully cross referenced with the book; and extensive bibliographies for each chapter."--BOOK JACKET.

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.