Geology of Mars Essay

1867 Words 8 Pages
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
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In addition, the crust of Mars contains more volatile elements such as sulfur and chlorine than Earth.
One of the most striking features of Mars is the Martian Dichotomy, which is the stark difference in the topography of the Northern and Southern Hemispheres. The two hemispheres vary greatly, with differences in elevation of up to 3 kilometers. The Northern Hemisphere is relatively flat, with impact craters scattered about. However, once you venture into the Southern Hemisphere, it is drastically different.
The Southern Hemisphere is extremely mountainous, with many valleys and peaks. It has a significantly higher elevation than the Northern Hemisphere, and is studded with impact craters. The crust is also significantly thicker in the Southern Hemisphere, with an average thickness of 58 kilometers in the Southern versus a 32 kilometer thickness in the Northern Hemisphere.
There are several theories as to why the dichotomy exists, and why it is so stark. One such theory is the Single Impact Hypothesis. This theory says that early in the formation of the planet, Mars was hit with a large asteroid, which would have created a large depression. This depression would account for the stark differences in elevation between the two hemispheres.
Scientists, however, have identified issues with this theory. The main detraction is that an impact of that size and magnitude would have left a circular impression on the planet. Most analysis of…