Water in Extrasolar Planets and Implications for Habitability

Exoplanet detection missions have found thousands of planets or planet candidates outside of the Solar System—some of which are in the habitable zone, where liquid water is possible at the surface. We give an overview of the recent progress in observations of water-rich exoplanets, detection of water in the atmosphere of gas giants and less-massive targets, and modelling of the interior and evolution of water layers in exoplanets. We summarise the possible habitability of water-rich planets and discuss the potential of future missions and telescopes towards the detection of water in the atmosphere of low-mass exoplanets or on their surface