On Earth, lakes provide favorable environments for the development of life and its preservation as fossils. They are extremely sensitive to climate fluctuations and to conditions within their watersheds. As such, lakes are unique markers of the impact of environmental changes. Past and current missions have now demonstrated that water once flowed at the surface of Mars early in its history. Evidence of ancient ponding has been uncovered at scales ranging from a few kilometers to possibly that of the Arctic ocean. Whether life existed on Mars is still unknown; upcoming missions may find critical evidence to address this question in ancient lakebeds as clues about Mars' climate evolution and its habitability potential are still preserved in their sedimentary record. Lakes on Mars is the first review on this subject. It is written by leading planetary scientists who have dedicated their careers to searching and exploring the questions of water, lakes, and oceans on Mars through their involvement in planetary exploration, and the analysis of orbital and ground data beginning with Viking up to the most recent missions. In thirteen chapters, Lakes on Mars critically discusses new data and explores the role that water played in the evolution of the surface of Mars, the past hydrological provinces of the planet, the possibility of heated lake habitats through enhanced geothermal flux associated with volcanic activity and impact cratering. The book also explores alternate hypotheses to explain the geological record. Topographic, morphologic, stratigraphic, and mineralogic evidence are presented that suggest successions of ancient lake environments in Valles Marineris and Hellas. The existence of large lakes and/or small oceans in Elysium and the Northern Plains is supported both by the global distribution of deltaic deposits and by equipotential surfaces that may reflect their past margins. Whether those environments were conducive to life has yet to be demonstrated but from comparison with our planet, their sedimentary deposits may provide the best opportunity to find its record, if any. The final chapters explore the impact of climate variability on declining lake habitats in one of the closest terrestrial analogs to Mars at the Noachian/Hesperian transition, identify the geologic, morphologic and mineralogic signatures of ancient lakes to be searched for on Mars, and present the case for landing the Mars Science Laboratory mission in such an environment. - First review on the subject by worldwide leading authorities in the field - New studies with most recent data, new images, figures, and maps - Most recent results from research in terrestrial analogs

From Habitability to Life on Mars explores the current state of knowledge and questions on the past habitability of Mars and the role that rapid environmental changes may have played in the ability of prebiotic chemistry to transition to life. It investigates the role that such changes may have played in the preservation of biosignatures in the geological record and what this means for exploration strategies. Throughout the book, the authors show how the investigation of terrestrial analogs to early Martian habitats under various climates and environmental extremes provide critical clues to understand where, what and how to search for biosignatures on Mars. The authors present an introduction to the newest developments and state-of-the-art remote and in situ detection strategies and technologies that are being currently developed to support the upcoming ExoMars and Mars 2020 missions. They show how the current orbital and ground exploration is guiding the selection for future landing sites. Finally, the book concludes by discussing the critical question of the implications and ethics of finding life on Mars. - Edited by the lead on a NASA project that searches for habitability and life on Mars leading to the Mars 2020 mission - Presents the evidence, questions and answers we have today (including a summary of the current state of knowledge in advance of the ESA ExoMars and NASA Mars 2020 missions) - Includes contributions from authors directly involved in past, current and upcoming Mars missions - Provides key information as to how Mars rovers, such as ExoMars and Mars 2020, will address the search for life on Mars with their instrumentation

“Sarah Stewart Johnson interweaves her own coming-of-age story as a planetary scientist with a vivid history of the exploration of Mars in this celebration of human curiosity, passion, and perseverance.”—Alan Lightman, author of Einstein’s Dreams WINNER OF THE PHI BETA KAPPA AWARD FOR SCIENCE • NAMED ONE OF THE BEST BOOKS OF THE YEAR BY The New York Times Book Review • Times (UK) • Library Journal “Lovely . . . Johnson’s prose swirls with lyrical wonder, as varied and multihued as the apricot deserts, butterscotch skies and blue sunsets of Mars.”—Anthony Doerr, The New York Times Book Review Mars was once similar to Earth, but today there are no rivers, no lakes, no oceans. Coated in red dust, the terrain is bewilderingly empty. And yet multiple spacecraft are circling Mars, sweeping over Terra Sabaea, Syrtis Major, the dunes of Elysium, and Mare Sirenum—on the brink, perhaps, of a staggering find, one that would inspire humankind as much as any discovery in the history of modern science. In this beautifully observed, deeply personal book, Georgetown scientist Sarah Stewart Johnson tells the story of how she and other researchers have scoured Mars for signs of life, transforming the planet from a distant point of light into a world of its own. Johnson’s fascination with Mars began as a child in Kentucky, turning over rocks with her father and looking at planets in the night sky. She now conducts fieldwork in some of Earth’s most hostile environments, such as the Dry Valleys of Antarctica and the salt flats of Western Australia, developing methods for detecting life on other worlds. Here, with poetic precision, she interlaces her own personal journey—as a female scientist and a mother—with tales of other seekers, from Percival Lowell, who was convinced that a utopian society existed on Mars, to Audouin Dollfus, who tried to carry out astronomical observations from a stratospheric balloon. In the process, she shows how the story of Mars is also a story about Earth: This other world has been our mirror, our foil, a telltale reflection of our own anxieties and yearnings. Empathetic and evocative, The Sirens of Mars offers an unlikely natural history of a place where no human has ever set foot, while providing a vivid portrait of our quest to defy our isolation in the cosmos.

The search for life on Mars—and the moral issues confronting us as we prepare to send humans there Does life exist on Mars? The question has captivated humans for centuries, but today it has taken on new urgency. As space agencies gear up to send the first manned missions to the Red Planet, we have a responsibility to think deeply about what kinds of life may already dwell there—and whether we have the right to invite ourselves in. Telling the complete story of our ongoing quest to answer one of the most tantalizing questions in astronomy, David Weintraub grapples with the profound moral and ethical questions confronting us as we prepare to introduce an unpredictable new life form—ourselves—into the Martian biosphere. Now with an afterword that discusses the most recent discoveries, Life on Mars explains what we need to know before we go.

Why has NASA not announced to the world the greatest scientific discovery ever made in the history of space exploration? Do you want to know what has really been discovered by the orbiters and rovers on the planet Mars? While scientists spend billions of dollars confirming that microbes live in the Martian soil, people sitting at home on their computers studying the Mars images are making far more astounding discoveries... they have found the possible archaeological remains of an extraterrestrial civilization. Hard to believe? Well, this challenging book invites you to take a look at the astounding pictures yourself and make up your own mind. Secret Mars presents over 160 incredible images taken by American and European spacecraft that reveal possible evidence of a civilization that once lived and may still live, on the planet Mars... powerful evidence that scientists are ignoring! This is the complete revised edition from the original 2013 publication in Britain. A visual and fascinating book!

Award-winning journalist Stephen Petranek says humans will live on Mars by 2027. Now he makes the case that living on Mars is not just plausible, but inevitable. It sounds like science fiction, but Stephen Petranek considers it fact: Within twenty years, humans will live on Mars. We’ll need to. In this sweeping, provocative book that mixes business, science, and human reporting, Petranek makes the case that living on Mars is an essential back-up plan for humanity and explains in fascinating detail just how it will happen. The race is on. Private companies, driven by iconoclastic entrepreneurs, such as Elon Musk, Jeff Bezos, Paul Allen, and Sir Richard Branson; Dutch reality show and space mission Mars One; NASA; and the Chinese government are among the many groups competing to plant the first stake on Mars and open the door for human habitation. Why go to Mars? Life on Mars has potential life-saving possibilities for everyone on earth. Depleting water supplies, overwhelming climate change, and a host of other disasters—from terrorist attacks to meteor strikes—all loom large. We must become a space-faring species to survive. We have the technology not only to get humans to Mars, but to convert Mars into another habitable planet. It will likely take 300 years to “terraform” Mars, as the jargon goes, but we can turn it into a veritable second Garden of Eden. And we can live there, in specially designed habitations, within the next twenty years. In this exciting chronicle, Petranek introduces the circus of lively characters all engaged in a dramatic effort to be the first to settle the Red Planet. How We’ll Live on Mars brings firsthand reporting, interviews with key participants, and extensive research to bear on the question of how we can expect to see life on Mars within the next twenty years.