The solidification of the inner core may have strengthened Earth's magnetic field.
Earth's core is a billion years old : Read more
Earth's core is a billion years old : Read more
It is clear that it is a SWAG
Iron is the most common siderophile element (well, it would be) [ https://en.wikipedia.org/wiki/Goldschmidt_classification#Siderophile_elements ].
"There is still no direct evidence about the composition of the inner core. However, based on the relative prevalence of various chemical elements in the Solar System, the theory of planetary formation, and constraints imposed or implied by the chemistry of the rest of the Earth's volume, the inner core is believed to consist primarily of an iron–nickel alloy.
At the known pressures and estimated temperatures of the core, it is predicted that pure iron could be solid, but its density would exceed the known density of the core by approximately 3%. That result implies the presence of lighter elements in the core, such as silicon, oxygen, or sulfur, in addition to the probable presence of nickel.[28] Recent estimates (2007) allow for up to 10% nickel and 2–3% of unidentified lighter elements.[4]"
[ https://en.wikipedia.org/wiki/Earth's_inner_core#Composition ]
why not iron-nickel in the interior of the earth also?
"Earth is unique in our solar system in that it has a magnetic field, and that it's habitable," study author Jung-Fu Lin, a geoscientist at the University of Texas at Austin, told Live Science. "Eventually our results could be used to think about why other planets in our solar system don't have magnetic fields."
See: https://www.iflscience.com/physics/scientists-reveal-birth-date-earths-inner-core/ See: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.078501
* Red algae is one of the largest phyla of algae, with more than 5,000 distinct species. They are almost exclusively multicellular marine algae, and many of the common seaweed varieties people eat belong to this group. They can be contrasted primarily with brown and green algae, and should not be mistaken with the phylum Dinoflagellata, which are algae that cause the so-called red tide. Although red slime algae is not particularly attractive physically, it is one of the most important things on the planet. It is responsible for an enormous amount of oxygen creation, and it is thought that if red slime algae didn’t exist, the skies of earth would not be blue.And we have not yet detected life on these planets devoid of magnetic field lines.
Hartmann352.
ancient science which was called as Kaalchakra
I'm a nuclear engineer and know what I am talking about.
If indeed the inner core formed around 1 to 1.5 billion years ago as the authors suggest, then this would coincide with the rise of simple multicellular life on Earth, such as red algae*, approximately 900 million years ago, resulting from the growth of the protective magnetic field.
The results of the thesis can be compared to similar studies of Mars and Earth. The comparisons between the three sibling planets give a more comprehensive picture of the solar wind effects on planetary atmospheres. For example Earth, with its strong magnetic field, has a larger loss of atmosphere to space than both Venus and Mars.