‘Forbidden’ substances on super-Earths may help sustain life
Moscow: “Forbidden” substances can increase heat transfer rates and strengthen magnetic fields on massive Earth-like planets that may eventually help harbour living organisms, scientists say.
Super-Earths are planets with a solid surface mass several times greater than the mass of the Earth.
Using mathematical models, scientists from the Moscow Institute of Physics and Technology (MIPT) “looked” into the interior of super-Earths and discovered that they may contain compounds that are forbidden by the classical rules of chemistry.
Earth-like planets consist of a thin silicate crust, a silicate-oxide mantle — which makes up approximately 7/8 of the Earth’s volume and consists more than 90 percent of silicates and magnesium oxide — and an iron core.
“We can say that magnesium, oxygen and silicon form the basis of chemistry on Earth and on Earth-like planets,” said Artem Oganov, head of the MIPT laboratory of computer design.
The Mg-Si-O system is the major Earth and rocky planet-forming system.
In the latest paper, the researchers attempted to find out which compounds may be formed by silicon, oxygen and magnesium at high pressures.
Using a novel algorithm, the researchers investigated various structural compositions of Mg-Si-O that may occur at pressures ranging from five to 30 million atmospheres.
Such pressures may exist in the interior of super-Earths like the recently discovered “Gliese 832c” which is five times heavier than the Earth or the mega-Earth “Kepler-10c” which is 17 times heavier than the Earth.
The results show that the interior of these planets may contain the “exotic” compounds MgSi3O12 and MgSiO6.
They have many more oxygen atoms than the MgSiO3 on the Earth.
Their properties are very different to normal compounds of magnesium, oxygen and silicon.
“Many of them are metals or semiconductors. This is important for generating more powerful magnetic fields on these planets,” said Oganov.
A more powerful magnetic field means more powerful protection from cosmic radiation and consequently more favourable conditions for living organisms.
The findings were presented in a paper published in the journal Scientific Reports.