While you might think that a planet covered entirely in water would be uninhabitable, a new study suggests that this may not be the case.
Researchers from the University of Chicago and Pennsylvania State University suggest that these ‘water worlds’ could in fact support alien life.
Dr Edwin Kite, who led the study, said: “This really pushes back against the idea you need an Earth clone – that is, a planet with some land and a shallow ocean.”
Life needs an extended period to evolve, and because the light and heat on planets can change as their stars age, scientists usually look for planets with some water and some land.
However, the new study suggests that water worlds could support life – in a different way.
By setting up a simulation with thousands of randomly generated planets, the researchers could simulate the evolution of their climates over billions of years.
Dr Kite explained: “The surprise was that many of them stay stable for more than a billion years, just by luck of the draw. Our best guess is that it’s on the order of 10 percent of them."
These lucky planets sit in the right location around their stars, and have the right amount of carbon, without having too many minerals and elements from the crust dissolved in the oceans.
This means the planets cycle carbon between the atmosphere and ocean only, keeping conditions stable enough to support life.
Dr Kite said: “How much time a planet has is basically dependent on carbon dioxide and how it’s partitioned between the ocean, atmosphere and rocks in its early years.
“It does seem there is a way to keep a planet habitable long-term without the geochemical cycling we see on Earth."
Source: Read Full Article