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¿

A collaborative effort by scientists studying terrestrial and extraterrestrial oceans

1. Preface [REPLACES EDITORIAL]2. "On the Habitability and Future Exploration of Ocean Worlds" by K. Hand et al.3. "The emergence of life" by E. Camprubi Casas et al.4. "Large ocean worlds with high-pressure ices" by B. Journaux et al.5. "Ice-ocean exchange processes in outer solar system satellites" by K. M. Soderlund et al.6. "Relict Ocean Worlds: Ceres" by M.-C. De Sanctis et al.7. "Experimental and Simulation Efforts in the Astrobiological Exploration of Exooceans" by R.-S. Taubner et al.8. "Microbial diversity and biosignatures: an icy moons perspective" by M. Jebbar et al.9. "Key Technologies and Instrumentation for Subsurface Exploration of Ocean Worlds" by B. Dachwald et al.