Life On Earth Came From Other Planets

This book discusses the big questions about how the discovery of extraterrestrial life, whether intelligent or microbial, would impact society and humankind.

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 field of planetary biology and chemical evolution draws together experts in astronomy, paleobiology, biochemistry, and space science who work together to understand the evolution of living systems. This field has made exciting discoveries that shed light on how organic compounds came together to form self-replicating molecules-the origin of life. This volume updates that progress and offers recommendations on research programs-including an ambitious effort centered on Mars-to advance the field over the next 10 to 15 years. The book presents a wide range of data and research results on these and other issues: The biogenic elements and their interaction in the interstellar clouds and in solar nebulae. Early planetary environments and the conditions that lead to the origin of life. The evolution of cellular and multicellular life. The search for life outside the solar system. This volume will become required reading for anyone involved in the search for life's beginnings-including exobiologists, geoscientists, planetary scientists, and U.S. space and science policymakers.

This edition of Science and Creationism summarizes key aspects of several of the most important lines of evidence supporting evolution. It describes some of the positions taken by advocates of creation science and presents an analysis of these claims. This document lays out for a broader audience the case against presenting religious concepts in science classes. The document covers the origin of the universe, Earth, and life; evidence supporting biological evolution; and human evolution. (Contains 31 references.) (CCM)

Aimed at the general reader, this is a readable 1998 account of the scientific basis for thinking there may be life elsewhere in the Universe.

What determines whether complex life will arise on a planet, or even any life at all? Questions such as these are investigated in this groundbreaking book. In doing so, the authors synthesize information from astronomy, biology, and paleontology, and apply it to what we know about the rise of life on Earth and to what could possibly happen elsewhere in the universe. Everyone who has been thrilled by the recent discoveries of extrasolar planets and the indications of life on Mars and the Jovian moon Europa will be fascinated by Rare Earth, and its implications for those who look to the heavens for companionship.

There is no gravity in space. The North Star never changes its position in the sky. Earth’s shadow causes the phases of the moon. You may have heard these common sayings or beliefs before. But are they really true? Can they be proven using science? Let’s investigate seventeen statements about space and find out which ones are right, which ones are wrong, and which ones still stump scientists! Find out whether astronauts really landed on the moon! Discover whether it’s true that the same side of the Moon is always dark! See if you can tell the difference between fact and fiction with Is That a Fact?