What is Ocean planet?
[[File:Oceanplanet_lucianomendez.JPG|thumb|A artists impression of what a ocean world with two moons may look like.]] An '''ocean planet''' (or '''ocean world''', '''water world''', '''aquaplanet''' or '''panthalassic planet''') is a type of [[terrestrial planet]] that contains a high amount of water. This may be a planet with ocean covering all of its surface (except maybe at the polar regions, where ice caps may exist), or a planet with a ocean bellow its surface (called a [[subsurface ocean]]). Ocean planets are also the name of planets that have other types of liquids on them such as liquid [[ammonia]], [[ethane]], or even [[lava]]. ==Habitation== A ocean planet covered in water may have conditions to support life.<ref>https://www.space.com/20728-new-alien-planets-oceans-life.html | What Might Alien Life Look Like on New 'Water World' Planets? | April 18, 2013</ref> This has been questioned though, since some studies suggest that water worlds may not be friendly to life, since [[chemical element|elements]] like [[phosphorus]] (a key part to [[DNA]]) may be hard to access, since it any be hidden in rocks at the bottom of the planet's oceans. Other problems here may be certain parts of the [[water cycle]] not working on an ocean planet, or the low amount of [[oxygen]] in the atmosphere.<ref>https://www.newscientist.com/article/2154137-ocean-covered-planets-may-not-be-the-places-to-search-for-life/ | Ocean-covered planets may not be the places to search for life | 21 November 2017</ref> With that being said, there are still possibilities for life on water planets. ==Possible ocean worlds== [[File:Kepler22b-artwork.jpg|thumb|[[Kepler-22b]] is a possible ocean world.]] There are a few planets that could be ocean planets. All of these are [[extrasolar planet|extrasolar planets]]. *[[Kepler-22b]] a rocky [[super-Earth]] that lies in the [[habitable zone]] of its host star. *[[Gliese 1214b]] a [[super Earth]] that circles its [[red dwarf]] star very close, but a deep ocean may exist under high pressure caused