Some planets previously considered “hellish” may actually be potentially habitable worlds.
According to Sci-News, a new study led by Professor Caroline Dorn from ETH Zurich (Switzerland) reveals that super-Earths with vast magma oceans and extremely humid atmospheres could be a form of habitable planet that we have overlooked.
Astronomical biology studies often search for life in worlds with temperate environments, resembling Earth in some way.
As a result, planets covered by magma oceans or those where mass and density measurements indicate excessively high water ratios are often dismissed.
Super-Earths covered by magma oceans could be habitable worlds in the future – (Image AI: Anh Thư).
While many previous studies have shown that water is essential for life, an excess of water—such as in oceanic worlds—can inhibit the emergence and evolution of life.
However, the publication in the journal Nature Astronomy points out that “ocean planets” might only have surface water comparable to Earth’s, as a significant amount of water may have been trapped in the core.
Their magma oceans are similar to the primordial magma oceans of Earth, and water dissolves very well in these magma oceans.
They also have iron cores. This core requires time to develop, as a significant amount of initial iron was also trapped in the magma.
This iron has combined with water molecules, pulling them down into the core over time.
A small amount of Earth’s water has also been concealed in the core in this manner. For larger planets—super-Earths that are about six times the size of Earth or more—water is even more likely to be hidden in the core.
In certain cases, iron can absorb water up to 70 times more than silicates.
Thus, finding a planet with measurements indicating a high water ratio does not mean that water is abundant on the surface.
If the outer crust of such a planet can cool and solidify like Earth did billions of years ago, water dissolved in the magma ocean could escape and rise to the surface during this process.
In other words, some super-Earths that seem hellish are actually undergoing a planetary evolution process similar to our world in the Hadean Eon, when the fiery globe gradually cooled and became a habitable world.
Hence, the authors conclude that even planets with relatively high water content have the potential to develop Earth-like living conditions.
Therefore, these enormous ocean worlds, relatively “old” like Earth, could be the next targets in the search for extraterrestrial life.
