Kepler-138d

Montreal Astronomers Spot Possible Water-Rich Exoplanets

Montreal Astronomers Spot Possible Water-Rich Exoplanets

Water wasn’t directly detected, but by comparing the sizes and masses of the planets to models, they conclude that a significant fraction of their volume — up to half of it — should be made of materials that are lighter than rock but heavier than hydrogen or helium (which constitute the bulk of gas giant planets like Jupiter). The most common of these candidate materials is water.