The global structure of Mars is well documented through viewings by scientists. However, without actually stepping foot on the planet, all we know of it is through observation. Due to this, the issue of plate tectonics on Mars is a contested issue. While scientists are sure that the core of Mars is not active, which means no plate tectonics; they cannot be sure that there was never a time when there were.
Mars was formed by materials that were released by the early solar nebula. Mars’ core is 1,300-1,500 km in radius and is not active. The lack of movement by the core leads to a lack of a magnetic field on the planet, and a lack of plate tectonics. Mars was formed very quickly, and the amount of accretion led to global melting. This allowed iron-rich melts to settle in the center of the planet, forming a core separate from the mantle, which is filled with silicate.
The lack of a moving core means that there is no magnetic field on Mars. However, the Mars Global Surveyor Mission, which ran from 1996-2001, saw large bands of magnetic anomalies on the crust, indicating that there was once a magnetic field. A loss of heat and solidification of the core caused the magnetic field to cease.
Allan Hills 84001, a meteorite found on Antarctica in 1984, contained 3.9-4.1 billion year old carbonates that held magnetized minerals, indicating that Mars had a magnetic field for the first 500 million years of its existence, and that it turned off approximately 4 billion years ago.
The cores of both Earth and Mars share some similarities, which can be attributed both planets being terrestrial and differentiated planets. Both have a central metal core, made up of iron and nickel, with a surrounding silicate mantle. The similarities, howe...
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