EntityQ3348698· pop 13· linked from 655 articlesMars ocean theorySign in to savetheory that nearly a third of the surface of Mars was covered by an ocean of liquid water early in the planet’s geologic historyConnectionsatmosphere of MarsEntityaxial tiltEntityareographyEntityHiRISEEntityNoachianEntitylist of missions to MarsEntityJournal of Geophysical ResearchEntitywaterEntityMarsEntityArctic OceanEntitytsunamiEntityasteroidEntitycarbon dioxideEntityThe New York TimesEntitymethaneEntityPhobosEntityDeimosEntitydigital object identifierEntityicebergEntityriver deltaEntityCategoriesHistorical oceansWater on Mars