A hycean planet (/ˈhaɪʃən/ HY-shən)[1] 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.
- ^ Paul Scott Anderson (30 August 2021). "Hycean planets might be habitable ocean worlds". Earth & Sky. Retrieved 30 August 2021.