Ocean Worlds | Habitability in the Outer Solar System and Beyond

This collection of scientific papers provides a state-of-the-art look at current knowledge on ocean worlds in our solar system and beyond. It is the result of a collaborative effort by scientists studying both terrestrial and extraterrestrial oceans, and analyzes the emergence of life and its survival on Earth as well as other potentially habitable planets and moons.
The papers examine the more remote provinces of our solar system, focusing on the icy moons of the giant planets, like Europa and Titan, as well as bodies like Ceres and putative extrasolar ocean worlds. Their potential for subsurface liquid water oceans are explored, as is as their astrobiological potential. The collection also takes a look at Earth’s own oceans, which offer important clues for the investigation of other ocean worlds.
In addition, the collection addresses the outstanding key scientific questions and measurements, technologies and laboratory experiments necessary for the exploration of ocean worlds known today.
Previously published in Space Science Reviews in the Topical Collection "Ocean Worlds”

Athena Coustenis studied Physics and Astrophysics at Pierre et Marie Curie Paris University and English Literature at La Sorbonne, but she managed to get two Masters and only one PhD. She is currently Director of Research with the French Center for Scientific Research based at Paris Observatory in Meudon, specializing in Planetology. She is currently the President of the European Space Sciences Committee, of the European Space Agency's Human Exploration and Science Advisory Committee, of the COSPAR Panel on Planetary Protection and of the Evaluation Science committee of the French National Center for Space Studies. She is a member of several other international advisory bodies, in particular of ESA and NASA. She has published more than 230 scientific papers, written 3 books and several chapters and she has given more than 350 presentations.
Rafael Rodrigo (PhD at the University of Granada in 1979) has been Director of the Institute of Astrophysics of Andalusia (1990-2004), where he was directly involved in the direction of many projects on Solar System Exploration. He has been the President of the Spanish National Research Council (CSIC) (2008-2012). He has been or is involved in many space missions (Rosetta, Cassini‐Huygens, Mars Express, Bepi‐Colombo, JUICE). He is currently a Research Professor at the Centro de Astrobiologia (CSIC), Madrid, and former Executive Director of the International Space Science Institute in Bern, Switzerland (2012-2018). Presently he is General Secretary for Research at the Spanish Ministry of Science and Innovation. He is the author or co‐author of more than 300 scientific publications.

Tilman Spohn is the executive Director of the International Space Science Institute in Bern, Switzerland. Before, he was director of the DLR Institute of Planetary Research in Berlin/Germany and a Professor of Planetology at the Westfälische Wilhelms-Universität Münster/Germany. He specializes in the thermodynamics of planetary interiors using modelling and space instrumentation, habitability of planets and the role of life in their geological evolution. He is the principal investigator of the Heat Flow and Physical Properties Package on the NASA InSight mission to Mars and was the principal investigator of the MUPUS package on the Rosetta lander Philae. He is a full member of the Academy of Astronautics and of Academia Europaea, a fellow of the American Geophysical Union and recipient of the European Geophysical Union Runcorn-Florensky Medal.

Dr. Kevin P. Hand is a planetary scientist and astrobiologist at NASA's Jet Propulsion Laboratory, where he directs the Ocean Worlds Lab. His research focuses on the origin, evolution and distribution of life in the solar system with an emphasis on moons of the outer solar system that likely harbor liquid water oceans. He is the Pre-Project Scientist for NASA's Europa Lander mission concept and was Co-Chair of the 2016 Europa Lander Science Definition Team. From 2011-2016 Hand served as Deputy Chief Scientist for Solar System Exploration at JPL. His fieldwork has brought him to Antarctica, the Arctic, the depths of Earth's ocean, the glaciers of Kilimanjaro and Mt. Kenya, and the desert of Namibia.

Alexander Hayes is an Associate Professor of Astronomy at Cornell University and Director of the Cornell Center for Astrophysics and Planetary Science. His flight project experience includes NASA's Cassini, MER, MSL, Mars2020, Europa Clipper, and Dragonfly missions. Prof. Hayes is the recipient of the Zeldovich Medal from COSPAR, the Ronald Greeley Early Career Award from AGU, the Young Procter Prize from Sigma Xi, and Extraordinary Young Scientist recognition from the World Economic Forum. Hayes sits on the COPAR Panel for Planetary Protection and the U.S. National Academies Committee for Astrobiology and Planetary Science. He earned an M.Eng in Applied Physics from Cornell University and a Ph.D. in Planetary Science from the California Institute of Technology.

Dr Karen Olsson-Francis is the Director of AstrobiologyOU at the Open University, UK. Her team investigates the scientific, governance and ethical implications of space exploration. Her background is in microbiology of extreme environments, she is particularly interested in unique biosignatures that can be used as evidence of life. She has been involved in a number of astrobiology experiments onboard the International Space Station, which involved studying the effect of simulated Mars, icy moon and low Earth conditions on microbial and biosignature survival. She is also the UK representative on the COSPAR Planetary Protection Panel and was involved in writing a white paper on planetary protection of the outer Solar System.

Frank Postberg is a planetary scientist leading a research group at the Institute of Geological Sciences at Freie Universität Berlin. He is Co-Investigator on a number of space missions, such as Cassini-Huygens, Europa Clipper, JUICE, and Destiny+. After majoring in Chemistry and Physics, he received his PhD in 2007. Dr. Postberg was granted the Heisenberg Stipend of the German Research Foundation (DFG) in 2014 and a Consolidator Grant of the European Research Council (ERC) in 2017. Since 2018 he is a professor at Freie Universität Berlin.
Dr. Christophe Sotin is the Chief Scientist for the Planetary Science Directorate at NASA's Jet Propulsion Laboratory. He created and directed the Laboratoire de Planetologie et Geodynamique de Nantes (France) before moving to Pasadena in 2007. He was co-investigator of the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft. He was responsible for the implementation of all the Titan observations by the VIMS instrument. He has co-authored more than 230 papers on the geology, and interior structure and dynamics of terrestrial planets, icy moons, and exoplanets. He was the recipient of the Medal 'Runcorn-Florensky' medal of the European Union of Geosciences in 2008 and has been a Member of IAA (International Academy of Astronautics) since 2003.
Dr. Gabriel Tobie is a planetary scientist at CNRS/Laboratoire de Planétologie et Géodynamique, where is the coordinator of the Icy worlds research group. He was granted in 2011 a Starting Grant from the European Research Council (ERC) to study chemical exchnage in icy worlds and in 2017 a grant from the Agence National de Recherche (ANR) to study aqueous alteration in icy worlds. He is contributed to the interpretation of the data gathered by the Cassini-Huygens mission, especially at Titan and Enceladus. He is co-Investigator on the 3GM and MAJIS instrument on ESA JUICE and SUDA on NASA Europa Clipper. As co-lead of the Geophysics/interior working group, he participates actively to the observation planning of the ESA JUICE mission.

François Raulin is professor emeritus at Paris Est Créteil University and is developing his research at LISA (Interuniversity Laboratory of Atmospheric Systems). He was director of LISA and of the federation of exobiology laboratories of the CNRS. He was president of the French Society of Exobiology and the ESA's Planetary Protection Working Group. He was IDS of the NASA-ESA Cassini-Huygens mission for Titan's chemistry and exobiology and co-investigator of CIRS (Cassini), ACP and GC-MS (Huygens). He was also co-investigator of the COSAC and COSIMA experiments of the European cometary mission Rosetta. He is Co-PI of the MOMA experiment of the ExoMars 2020 mission. He is a member of the Planetary Protection Working Group of ESA, the COSPAR Planetary Protection Panel and the European Space Science Committee. He is the author or co-author of more than 300 publications.

Nicolas Walter is the Chief Executive Officer of the European Science Foundation. Through his 18 years in the organisation, he been involved in many science policy initiatives in the domains of European marine, space, polar and materials science. Nicolas was the Executive Scientific Secretary of the ESF's European Space Sciences Committee, ESSC, that represents the space science community in Europe. In this role, Nicolas has coordinated the ESSC activities and the production of high-level independent scientific advice to key stakeholders, including ministerial delegations, space agencies and the European Commission. Over the past years, Nicolas has also been instrumental in the development of the executive offices of the Europlanet Society, the recently created European platform for planetary scientists, and of the European Astrobiology Institute, the first institutional grouping of research organisations interested in astrobiology.

Jonas L'Haridon is a Junior Science Officer at the EuropeanScience Foundation, where he is mainly involved with the development of the Europlanet Society, management of the Europlanet 2024 Research Infrastructure as well as in the activities of the European Space Sciences Committee (ESSC). He is a planetary scientists and geologist by training, and studied fluid-rock interactions after the burial of sediments on Mars while he was involved in the NASA Mars Science Laboratory Mission as a collaborating scientists. He obtained his PhD from the University of Nantes in 2018.