https://www.universetoday.com/154461/we-...tic-field/
EXCERPTS: A new study published in Nature Communications tries to answer that question, like many studies before. The title is “Stratification in planetary cores by liquid immiscibility in Fe-S-H.” The leading authors are Professor Kei Hirose from the University of Tokyo’s Department of Earth and Planetary Science and Ph.D. student Shunpei Yokoo in the Hirose lab.
[...] Hirose and his team think that initially, two immiscible liquids became separated in Mars’ core. “While separated denser liquids stayed at the deepest part, lighter liquids migrated upward and mixed with the bulk liquid core, which could drive Martian core convection,” they write. But in the region where the two liquids separated, something else happened. “At the same time, gravitationally stable, compositional stratification should have developed in a region where liquid separation took place. Eventually, Mars’ entire core became stratified, which ceased convection.”
Scientists already knew when convection ceased and Mars lost its magnetic shield. That happened about 4 billion years ago. This study explains why convection ended, leading to the loss of the magnetic shield. It also explains how it began. “The separation of immiscible S-rich and H-rich liquids could have been responsible for both the onset and termination of Martian core convection and dynamo action,” they write in their paper.
Once the two liquids separated, Mars was doomed. There was no more convection, no more magnetism, no more atmosphere, and no more water. The exact timeframe is unknown, but the result was a dead planet. However, this is just one study, and we don’t have the complete picture... (MORE - missing details)
EXCERPTS: A new study published in Nature Communications tries to answer that question, like many studies before. The title is “Stratification in planetary cores by liquid immiscibility in Fe-S-H.” The leading authors are Professor Kei Hirose from the University of Tokyo’s Department of Earth and Planetary Science and Ph.D. student Shunpei Yokoo in the Hirose lab.
[...] Hirose and his team think that initially, two immiscible liquids became separated in Mars’ core. “While separated denser liquids stayed at the deepest part, lighter liquids migrated upward and mixed with the bulk liquid core, which could drive Martian core convection,” they write. But in the region where the two liquids separated, something else happened. “At the same time, gravitationally stable, compositional stratification should have developed in a region where liquid separation took place. Eventually, Mars’ entire core became stratified, which ceased convection.”
Scientists already knew when convection ceased and Mars lost its magnetic shield. That happened about 4 billion years ago. This study explains why convection ended, leading to the loss of the magnetic shield. It also explains how it began. “The separation of immiscible S-rich and H-rich liquids could have been responsible for both the onset and termination of Martian core convection and dynamo action,” they write in their paper.
Once the two liquids separated, Mars was doomed. There was no more convection, no more magnetism, no more atmosphere, and no more water. The exact timeframe is unknown, but the result was a dead planet. However, this is just one study, and we don’t have the complete picture... (MORE - missing details)