Photo: NASA / JPL-Caltech
Scientists at the University of Chicago and the University of Pennsylvania refuted the popular assumption that planet completely covered by ocean, not suitable for life. About it reported in a press release Phys.org.
It is known that for the existence of life requires liquid water, it must be a lot over a long period of time (sufficient for the evolution). The climate can vary significantly, therefore for the survival of organisms need also geochemical cycles, which, for example, maintaining a balance between volcanic emissions and fixation of atmospheric gases rocks. Many scientists believe that the planet is covered by ocean, lifeless as they lack many cycles of substances that are on the Earth.
However, in the new work, the researchers showed that the geochemical cycles it is not always necessary for the existence of life. Experts have modeled several scenarios of changes of temperature and chemical composition of the oceans over billions of years for rocky planets. It turned out that quite a lot of water worlds from the very beginning of its existence, to maintain stable and favorable conditions for life for quite a long time. The reason for this is the pressure exerted by the ocean on the earth’s crust, resulting in hampered the exchange of substances between the mantle and the hydrosphere.
Thus, the existence of living organisms on oceanic planets does not depend on geochemical cycles, and the initial distribution of carbon and other substances between water shell, atmosphere and crust. Moreover, red dwarfs can be suitable candidates for the role of the parent star in the system with such a planet, because they are heated more slowly than the Sun, giving life more time to develop.
Video, photo All from Russia.