The Earth’s core is leaking helium-3, a rare element that could fuel nuclear fusion and could be the key to the origin of life.
Scientists think they may have solved the mystery of how helium-3, a rare element that has attracted interest as a potential fuel source for nuclear fusion reactors, is leaking out. from the Earth’s core – according to a new study.
The study suggests that this ancient material seeped out from the core into the Earth’s outer layers, the mantle and crust, by reactions with magnesium oxide.
The discovery could help uncover Earth’s mysterious interior regions, as well as understand how life appeared on Earth and whether it could exist elsewhere in the universe.
Helium-3 is an isotope of the element helium, with only one neutron in its nucleus instead of two. Most helium-3 was formed shortly after the formation of the universe, making it only slightly “younger” than the universe.
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Beyond this original source, helium-3 is a hot topic for scientists working on nuclear fusion , exploring a possible form that could provide unlimited clean energy. . The properties of helium-3 make it a potential fuel source for fusion reactions. For that reason, one example is scientists working on mining helium-3 “stuck” on the Moon.
When the Earth began to form from gas and dust about 4.5 billion years ago, primordial helium-3 was forced into the mix. As a result, large reservoirs of these isotopes were locked in the Earth’s core, located about 2,900km below our feet. Helium-3 is rare on Earth’s surface , but traces of it can be found in volcanic rock in the ocean, suggesting that there is an unknown mechanism that is allowing the gas to escape from the core.
Now, two scientists have suggested that a mineral called magnesium oxide (MgO) , common in the Earth’s core, could assist helium-3 from the core to leak into the Earth’s crust and beyond. .
In addition to explaining how the rare element helium-3 escapes from the Earth’s core, the study also provides a “pathway to uncovering processes in the core”, helping to uncover how the Earth works. becomes the place where life emerges. This is reported in a new study published in the journal Nature Geoscience.
According to the study’s authors, Jie Deng and Zhixue Du, two geophysicists from Princeton University (USA) and the Guangzhou Institute of Fossils and Geology (China): “helium is considered to be a key marker for process deep within the Earth because the core is thought to be the home of the primordial isotope helium-3”.
“However, how helium moves from the core to the Earth’s crust is still unclear,” the team said.
Here, we use calculations to show that helium readily enters magnesium oxide at the boundary between the Earth’s core and mantle. This suggests that magnesium oxide escaping from the core can introduce significant amounts of helium into the mantle.”
Jie Deng and Zhixue Du are not the first scientists to realize that magnesium oxide compounds in the Earth’s core may play an important role in many processes affecting life on the Earth’s surface. Previous studies have shown that the movement of MgO from the core up has helped to create the dynamics of the Earth over the past few billion years, creating the planet’s magnetic field. This magnetic field protects us from harmful radiation and stabilizes the atmosphere we need to sustain life.
As the MgO floats up to the boundary between the outer core (made up of liquids) and the Earth’s mantle, where the temperature is lower than the core, it “dissolves” , which means transitioning from a copper mineral. into separate crystalline phases. MgO pulls helium-3 with it from the mixed liquid iron core to the boundary between the core and the Earth’s mantle, where decomposition carries both substances into the mantle.
“This core-wide convection, driven by the release of MgO, can efficiently transport helium from the deep core to the boundary,” scientists Deng and Du said in their study. boundary between core and mantle”.
“We also modeled the expected helium flux due to magnesium oxide degradation since core formation, suggesting that core-resolved magnesium oxide may have continuously fed helium from the core into the largely transparent mantle. Earth’s history, imprinting primordial helium into the mantle material,” the researchers noted.
While the two scientists say more research is needed to understand these processes, their new study offers a new piece to the mystery of the Earth’s core, the farthest region of our world, and identify the mysterious origin of helium-3 on the planet’s surface.
In addition, Deng and Du have suggested that the demineralization of minerals from the core could enrich the mantle and mantle with various elements, including those that have led to the emergence of life. on the earth.