Mars is more similar to Earth than you might think! For one, Mars also has tectonic motion, says a UCLA scientist. Yes, there are tectonic plates on Mars that move, create huge gorges and also develop prominent fault lines, just like they do on Earth. But then, they are not as similar as a naïve generalization might suggest.
Prof. An Yin, professor of Earth and space sciences explains why:
Mars is at a primitive stage of plate tectonics. It gives us glimpse of how the early Earth may have looked and may help us understand how plate tectonics began on Earth.
Deeper and Longer than anything else!
At the center of his research, lies the huge canyon between two regions, called the Valles Marineris (Latin for “Valley of Mariner”, after the Mariner Mars craft). With vertical cliffs, jagged rocks and a length of nearly 2500 km – about 9 times that of the Grand Canyon here on Earth – this is clearly a geologic goldmine! How did it form?
Yin argues that the forces at play are the familiar forces which generate steep cliffs here on Earth, namely the tectonic forces. The Valles Marineris, he argues, is actually a fault line and the forces have pushed up and submerged rocks, just like in Death Valley, California, which was also formed by tectonic action. And just for records of the superlatives, this is the deepest and longest canyon known in the Solar System.
The plates on Mars number just two, as compared to seven on Earth. They also move much slower than their terrestrial cousins. Mars being about half the size of Earth explains this slow motion – the initial ball of molten material was much more stable and there was less thermal energy to drive the whole process, which would’ve fragmented the crust even further. However, Yin thinks that the planet is on its way to becoming more fractured.
What About Mars-quakes?
Slow movement between plates and just one stable fault line means that Mars-quakes are way less frequent than earthquakes. The rate of movement hasn’t been ascertained – it’s just that it’s slow! Yin, who uses data obtained from the satellite images taken by the THermal Emission Imagine System (THEMIS) aboard the Mars Odyssey spacecraft and also from the High Resolution Imaging Science Experiment (HiRISE) aboard the Mars Reconnaissance Orbiter (MRO), thinks more data collected in the next year or so will help in answering these questions.
Prof. Yin’s paper is set to appear in the journal Lithosphere soon.