In an era of public Mars fascination, this book offers an objective presentation of the challenges of crewed Mars missions and discusses scenarios of Mars settlements under scientific, technical, social, economic , ethical and political aspects. With the aim to make the reader comprehend what is plausible and what is at stake, the book tries to clarify misconceptions and half-truths spreading rapidly in the public. The authors argue that approximations and misinformation should be countered for two main reasons. First, to avoid missing out on the benefits that Mars exploration may bring, including major scientific discoveries and an inspiring, federative human endeavor. Second, to remediate dangerous delusions - such as the idea that humanity could be transferred there should the Earth become inhabitable in the near term. In preparation for this book a group of European, world-renowned scientists from fields as diverse as astronomy, planetology, geology, biology, philosophy, or economics, as well as astronauts and science-fiction writers, was gathered to discuss Mars missions ranging from near-term robotic missions, all the way to large-scale settlements and even the feasibility of terraforming. For each, they draw arguments from their domains of expertise to discuss what is feasible and what is desirable. The result provides researchers with an objective review of the field, policy makers with a reference to make informed decisions, and the general public with a tool to form educated opinions.

Autorentext

Cyprien Verseux: Junior Research Group Leader of the Laboratory of Applied Space Microbiology (LASM) at the University of Bremen's Center for Applied Space Technologies and Microgravity (ZARM). His young research group focuses on the development of bio-processes in support of future crewed missions to the Moon and Mars. Beside his work in the laboratory, he has conducted field work, most notably during a one-year appointment as the Station Leader and Glaciologist at the Concordia research station (Antarctica) and as the Crew Biologist in the one-year, NASA-funded HI-SEAS IV mission (Mauna Loa volcano, Hawaii).

Kirsi Lehto is a Molecular biologist, **lecturer in molecular biology, and in astrobiology. She is author of: Teerikorpi, P., Valtonen, M., Lehto, K., Lehto, H., Byrd, G., and Chernin, A., 2009,The Evolving Universe and the Origin of Life. The Search for Our Cosmic Roots. Springer. ISBN: 978-0-387- 09533-2, 508 pp. Second edition. 2019. ISBN 978-3-030-17920-5; two books on astrobiology in Finnish, e.g. Astrobiologia (Ursa, the science book of the year 2019 in Finland).

Michel Viso: A veterinary doctor by training, was selected as a French Astronaut by CNES (without flight) and held a position of Project scientist at CNES for numerous biological space experiments. He was then responsible for Planetary protection for CNES, representing France in various international committees from 1999 to 2021. He has simultaneously been Programme Scientist for Astrobiology and Exoplanets at CNES for more than 15 years before retiring. He is currently working as a science advisor for

Innovaxiom, a company specialised in communication for science andtechnology. He recently joined the Solar System Exploration Panel of the European Space Science Committee. He was a Book Editor of the Encyclopedia of Astrobiology, Springer, 2011, 2015, 2023.

Muriel Gargaud is an Astrophysicist and Director of Research at CNRS (Centre national de la recherche scientifique). She has lead several large publishing collaborations

as Chief Editor of 1) "Encyclopedia of Astrobiology", Springer, 2011, 2015, 2023; 2) "Young sun, early earth and the origins of life: lessons for astrobiology", Springer, 2012; 3) "From suns to life: a chronological approach to the history of life on Earth", Springer, 2006*; 4) Lectures in astrobiology, Vol.1, Springer*, 2005; **5) Lectures in astrobiology, Vol.2, Springer, 2006. Since 2019 she is the vice chair of the European Astrobiology Institute.