For thousands of years, humans have wondered whether we're alone in the cosmos. Now, for the first time, we have the technology to investigate. The question should have an obvious answer: yes or no. But once you try to find life elsewhere, you realize it is not so simple. How do you find it over cosmic distances? What actually is life?
Astronomer Lisa Kaltenegger works from Carl Sagan's former office at Cornell University, where she built a team of tenacious scientists from many disciplines to find life on faraway worlds, using Earth's diverse biosphere and its history as a Rosetta Stone. With infectious enthusiasm, she provides an eye-opening insider's guide to the most unusual exoplanets that have shaken our worldview – planets covered in oceans of lava, lonely wanderers lost in space, and others with more than one sun in their sky – as well as the best contenders for Alien Earths. She also shows how close imagined scifi worlds come to reality.
We live in an incredible new epoch of exploration. As our witty and knowledgeable tour guide, Professor Kaltenegger shows how we discover not merely new continents, like the explorers of old, but whole new worlds circling other stars – and how we could spot life there. Worlds from where aliens may even be gazing back at us. What if we're not alone?
Lisa Kaltenegger is the Director of the Carl Sagan Institute to Search for Life in the Cosmos at Cornell University and an Associate Professor in Astronomy. She is a pioneer and world-leading expert in modelling potential habitable worlds and their detectable spectral fingerprint. Professor Kaltenegger has served on NSF and NASA committees and is a Science Team Member of NASA's TESS Mission as well as the NIRISS instrument on the James Webb Space Telescope.
Professor Kaltenegger is the recipient of numerous international prizes and awards, including being a European Commission Role Model for Women in Science and Research. She was named one of America's Young Innovators by Smithsonian Magazine, an Innovator to Watch by TIME Magazine, and stars in the IMAX 3D movie The Search for Life in Space. Asteroid Kaltenegger7734 is named after her.
"In the grand tradition of Carl Sagan and Neil deGrasse Tyson, we now have a new tour guide to the cosmos. Professor Lisa Kaltenegger takes us along on the quest to solve one of the greatest mysteries of existence: are we alone in the universe? In Alien Earths, Kaltenegger – one of the pioneers leading the way – reveals what we've already discovered, and even more breathtakingly, what we might find."
– Steven Strogatz, author of Infinite Powers
"In Kaltenegger's exhilarating exploration of the state of the Earth-hunting art, she welcomes us into the latest strategies for finding life at interstellar distances. Kaltenegger is that precious rarity, a leading scientist with an infectious passion for her subject and the talent to connect. Read this book and then gaze up at the night sky to find the stars sparkling even brighter with possibility."
– Ann Druyan, co-creator of Contact, co-writer Cosmos
"The odds are overwhelming that something's alive out there. But will we ever see a sign of life on a planet circling a distant star? And, if we do, will we recognize it? This fascinating and tantalizing book points the way to YES."
– Alan Alda
"Do you want to prepare yourself for the next 'Copernican revolution'? Then read Lisa Kaltenegger's book! Fascinating."
– Michel Mayor, Winner of the Nobel Prize in Physics
"In Alien Earths, Lisa Kaltenegger, a skillful educator, offers first-hand access to her expertise on the search for planets in the universe, and the life they may contain. Along the way, Lisa's breezy narrative style invites you to experience with her the challenges and joys of being a scientist on the frontier of discovery."
– Neil deGrasse Tyson, Astrophysicist, American Museum of Natural History
"Effervescent with ideas and edge-of-your-seat discoveries, Alien Earths provides a front-row seat to the astonishing era we live."
– Caleb Scharf, Director of Astrobiology, Columbia University, author of The Zoomable Universe
"Lisa Kaltenegger is an international leader in the discovery and analysis of exoplanets [...] Moreover, she is a brilliant expositor. I eagerly await what will surely be a riveting book."
– Lord Martin Rees, Astronomer Royal
"Lisa Kaltenegger is in the best possible position to offer this timely and accessible overview of the rapidly evolving and exciting field of exoplanets, expertly illuminating the questions we have begun to answer, and the many that we can expect to be resolved in the years and decades to come. Linking our understanding of alien worlds (and the possibility of life) to the grand story of Earth's own past, this is an engaging and personal book that couldn't be more up to date. Read Alien Earths, and feel your cosmic perspective shift just a little on its axis."
– Alastair Reynolds, science fiction writer and former ESA scientist
"If you've ever wondered if we're alone in the cosmos – and Dr. Kaltenegger is certain you have, start with Alien Earths. With her combined degrees in astronomy and engineering, she presents a primer on the geology, physics, chemistry, biology, and ultimately mathematics of places just like Earth- which she sets about seeking every (Earth) day. She learned the rudiments of extraterrestrial lifestyles, while overcoming no shortage of sexism. Could there be alien others out there wondering what it took for life to get a start on our special world? She'll show you; the answer is in the sky, our window on the cosmos. Read on!"
– Bill Nye, CEO, The Planetary Society (and former student of Carl Sagan)
"An erudite and highly readable inside view of the science and emerging discoveries of this remarkable new era."
– Charles Cockell, author of Taxis from Another Planet
"What a fascinating glimpse into the creative work of exobiologists, humankind's exciting search for life elsewhere in the universe, and the tantalizing facts we've learned thus far. I was enchanted"
– Diane Ackerman, author of The Zookeeper's Wife