Free Astronomy Magazine March-April 2023

MARCH-APRIL 2023 ASTRO PUBLISHING with a warlike species so greedy and prone to devastating their home planet? The risk of con- tacting a civilization that is dan- gerous in various respects, com- bined with the technical diffi- culties and the onerousness of undertaking “conversations” with other planets, is the basis of one of the most classic so- lutions to the Fermi paradox: everyone is listening but no one is transmitting. This scenario would be very likely, especially if the number of technological civilizations were small. If they were very numerous, it is un- likely that those civilizations would all adopt the same isola- tionist policy. As speculative as this entire discussion is, our cur- rent notions of an exo-civiliza- tion scenario that bases itself on a marked rarity of techno- logical civilizations appears to be the most reasonable, as well as the most reassuring for us who are only now leaning out into the larger galaxy. If this “rare civilization” sce- nario is the case, our feeble electromagnetic signals have almost no chance of reaching an alien receiving device. The whole question is not just a mental exercise or, at best, a philosophical dissertation. De- pending on how the probabili- ties of a contact are assessed, the propensity to finance SETI programs changes considerably. Take the most sensational ex- ample, Breakthrough Listen, started in January 2016 by Rus- sian-Israeli billionaire Yuri Mil- ner with $100 million to spread over 10 years. It is a program that aims to search for any radio and laser signals coming from the nearest one million stars and from the 100 closest galaxies. The observations will ET, are you out there? — The question of intelligent life on other worlds Is there anybody out there? Are there other intelligent life forms lurking in outer space – or are they already here? This calm, intelligent and witty survey of the history of humankind’s search for extraterrestrial life brilliantly outlines the historical, fictional, speculative and emerging scientific opinions on what alien life might be like. The fast-moving narrative examines facts, dispels myths and focuses on the possibilities lurking in space. In a popular and easy-to-read style, the author uses current research to speculate what life is like on exoplanets, how we might communicate with it, and what Earth might seem like to visitors. Is anybody out there? Are we alone? Or is the universe teeming with intelligent life? Can we expect extraterrestrial civilizations to be common? Oc- casional? Rare? In this wide-ranging Assessment, historian/writer W. H. Collier explores the probabilities of the existence of extra- terrestrial, technological life based on the latest scientific find- ings. Collier undertakes a thorough analysis of just what it would take for technological societies to arise on other planets. From quantifying the number of habitable planets, to examining the genesis and development of life on this planet, to grappling with the emergence of intelligence in our own species, Collier leaves no stone unturned. Are we alone? — Humankind’s search for extraterrestrial civilizations Earth revolves around one of billions of stars in the Milky Way, which is but one of billions of galaxies in the known universe. With odds like this, it seems likely that humankind is not alone. The cutting edge of science promises to provide clues to a de- finitive answer, and steady progress is being made by some of the world’s brightest minds. Are We Alone? is a book for the curious that explores complex concepts in an accessible man- ner. From single-celled organisms to the super intelligent be- ings of science fiction lore, Are We Alone? examines the intriguing forms that life could take and the conditions required for it to exist beyond earthly confines. First contact — Scientific breakthroughs in the hunt for life beyond Earth Science reporter Marc Kaufman takes readers around the globe, into space, and miles below Earth’s surface to show how the search for life on other planets is changing the way humans think about their own history, about what it means to be human, and about what, exactly, life is. First Contact is the first book to bring together recent developments across many com- peting branches of science, from microbiology to geochemistry, physics, and astronomy, all racing to verify what was once deemed impossible. Kaufman demystifies the key points behind the rigorous science and advanced technology that is edging ever closer to the most important discovery of modern times.