Other Earths Alien Life

An insider's look at the cutting-edge science of today's planet hunters In Strange New Worlds, renowned astronomer Ray Jayawardhana brings news from the front lines of the epic quest to find planets—and alien life—beyond our solar system. Only in the past two decades, after millennia of speculation, have astronomers begun to discover planets around other stars—thousands in fact. Now they are closer than ever to unraveling distant twins of the Earth. In this book, Jayawardhana vividly recounts the stories of the scientists and the remarkable breakthroughs that have ushered in this extraordinary age of exploration. He describes the latest findings--including his own—that are challenging our view of the cosmos and casting new light on the origins and evolution of planets and planetary systems. He reveals how technology is rapidly advancing to support direct observations of Jupiter-like gas giants and super-Earths—rocky planets with several times the mass of our own planet—and how astronomers use biomarkers to seek possible life on other worlds. Strange New Worlds provides an insider's look at the cutting-edge science of today's planet hunters, our prospects for discovering alien life, and the debates and controversies at the forefront of extrasolar-planet research. In a new afterword, Jayawardhana explains some of the most recent developments as we search for the first clues of life on other planets.

PEN Literary Award Winner: “The best, most entertaining examination of the possibility of other life in the universe since [Carl] Sagan’s best work.” —Boulder Daily Camera It’s been decades since Carl Sagan first addressed the general public about the possibility of extraterrestrial life from a scientist’s perspective. We’ve learned a lot in those years, and now planetary scientist David Grinspoon investigates the big questions: How widespread are life and intelligence in the cosmos? Is life on Earth an accident, or in some sense the “purpose” of this universe? And how can we, working from the Earth-centric definition of “life,” even begin to think about the varieties of life-forms on other planets? In accessible, lively prose, and using the topic of extraterrestrial life as a mirror with which to view human beliefs, evolution, history, and aspirations, Grinspoon takes us on a three-part journey—the history of our expanding awareness of other planets and our ideas on alien life dating back to the earliest days of astronomy; the science of cosmic evolution and the evolution of life on Earth, including a critique of the “Rare Earth hypothesis”; and the beliefs that humans hold, addressing the limits of our ability to conceptualize or communicate with intelligent aliens and the scientific and philosophical implications of far-future evolutionary possibilities. Rich in personal and often amusing anecdotes, Lonely Planets explores the shifting boundary between planetary science and natural philosophy, and reveals how the search for extraterrestrial life unites our spiritual and scientific quests for connection with the cosmos. Includes a new foreword about recent Mars discoveries “An outstanding introduction to cosmic evolution.” —San Jose Mercury News “[A] terrific book.” —San Diego Union-Tribune “A personable chat on life, the universe and everything.” —Publishers Weekly

In the search for other habitable planets, perhaps the most fascinating question that has persistently captivated humans has been: is there life out there? Eschewing science fiction fantasies, this title looks at the hard research behind the possibility of extraterrestrial life. Theories, studies, and advances of exobiologists-scientists who study life in outer space-are presented, alongside more philosophical questions on the implications of life beyond Earth. Discussions of the definition of life, personhood, and the qualities of extremophiles (animals that survive under extreme conditions) bring this discussion to intriguing and unexpected places.

The captivating possibilities of extraterrestrial life on exoplanets, based on current scientific knowledge of existing worlds and forms of life It is now known that we live in a galaxy with more planets than stars. The Milky Way alone encompasses 30 trillion potential home planets. Scientists Trefil and Summers bring readers on a marvelous experimental voyage through the possibilities of life--unlike anything we have experienced so far--that could exist on planets outside our own solar system. Life could be out there in many forms: on frozen worlds, living in liquid oceans beneath ice and communicating (and even battling) with bubbles; on super-dense planets, where they would have evolved body types capable of dealing with extreme gravity; on tidally locked planets with one side turned eternally toward a star; and even on "rogue worlds," which have no star at all. Yet this is no fictional flight of fancy: the authors take what we know about exoplanets and life on our own world and use that data to hypothesize about how, where, and which sorts of life might develop. Imagined Life is a must-have for anyone wanting to learn how the realities of our universe may turn out to be far stranger than fiction.

The search for life in the solar system and beyond has to date been governed by a model based on what we know about life on Earth (terran life). Most of NASA's mission planning is focused on locations where liquid water is possible and emphasizes searches for structures that resemble cells in terran organisms. It is possible, however, that life exists that is based on chemical reactions that do not involve carbon compounds, that occurs in solvents other than water, or that involves oxidation-reduction reactions without oxygen gas. To assist NASA incorporate this possibility in its efforts to search for life, the NRC was asked to carry out a study to evaluate whether nonstandard biochemistry might support life in solar system and conceivable extrasolar environments, and to define areas to guide research in this area. This book presents an exploration of a limited set of hypothetical chemistries of life, a review of current knowledge concerning key questions or hypotheses about nonterran life, and suggestions for future research.

An astronomy professor at Harvard University discusses the possibilities of finding other worlds that sustain alien life forms, citing recent breakthroughs in biology and exoplanetary astronomy, including the recent discovery of arsenic-based bacteria in a California lake.

Inside the epic quest to find life on the water-rich moons at the outer reaches of the solar system Where is the best place to find life beyond Earth? We often look to Mars as the most promising site in our solar system, but recent scientific missions have revealed that some of the most habitable real estate may actually lie farther away. Beneath the frozen crusts of several of the small, ice-covered moons of Jupiter and Saturn lurk vast oceans that may have existed for as long as Earth, and together may contain more than fifty times its total volume of liquid water. Could there be organisms living in their depths? Alien Oceans reveals the science behind the thrilling quest to find out. Kevin Peter Hand is one of today's leading NASA scientists, and his pioneering research has taken him on expeditions around the world. In this captivating account of scientific discovery, he brings together insights from planetary science, biology, and the adventures of scientists like himself to explain how we know that oceans exist within moons of the outer solar system, like Europa, Titan, and Enceladus. He shows how the exploration of Earth's oceans is informing our understanding of the potential habitability of these icy moons, and draws lessons from what we have learned about the origins of life on our own planet to consider how life could arise on these distant worlds. Alien Oceans describes what lies ahead in our search for life in our solar system and beyond, setting the stage for the transformative discoveries that may await us.