Back Planeta hiceànic Catalan Hyceánská planeta Czech Hyzänischer Planet German Υκεάνιος πλανήτης Greek Planeta hicéano Spanish سیاره هایسین Persian Hycean-planeetta Finnish Planète-hycéan French Pianeta hycean Italian ハイセアン惑星 Japanese
A hycean planet (/ˈhaɪʃən/ HY-shən) is a hypothetical type of exoplanet that features a liquid water ocean underneath a hydrogen-rich atmosphere. The term hycean is a portmanteau of hydrogen and ocean.