Mars' early crust may have been more complex than previously believed. Also, it may even have been similar to the crust on Earth.
Understanding what the planets of our solar system are like is of great importance. By studying how other planets came into existence, we can find new clues on how our own planet formed. Mars, for example, is considered to have been very much like Earth billions of years ago. Throughout the years, we have found important, previously unknown information about Mars. The Red planet was similar to Earth and had oceans, rivers, lakes, and an atmosphere that could have supported life. Rovers, landers, and orbiters have offered unprecedented details about Earth’s neighbor. And more data keeps on coming every day. Now, a new study offers us insight into the Martian crust and sheds light on the planet’s formation.
Mars’ early crust may have been more complex than previously believed. Also, it may even have been similar to the crust on Earth. Various forms of volcanism and flowing lava over billions of years formed the Martian surface, which is uniformly basaltic. The crustal history of Mars has been relatively straightforward since the planet has not undergone full-scale surface remodeling as Earth’s continents have. Researchers have found significantly higher concentrations of silicon in Mars’ southern hemisphere than those expected in purely basaltic settings, according to a new study. Space rocks that crashed into Mars had uncovered the silica concentration, excavating material embedded thousands of feet below the surface.
Silica and why its important
According to Valerie Payré, assistant professor in the Department of Earth and Environmental Sciences at the University of Iowa and co-author of the study, there is more silica in the composition, which makes the rocks, not basalt. This indicates that the crust on Mars has a much more complicated history than previously thought. “So, it’s more about understanding that process, and especially what it means for how Earth’s crust first formed.” The formation of Mars is believed to have occurred about 4.5 billion years ago. While there are no exact answers to how the Red Planet formed, there are theories. According to one theory, Mars formed from a titanic collision of rocks in space, which, when heated intensely, spawned magma oceans in a liquefied state. There is a theory that the magma ocean gradually cooled, creating a basaltic crust.
Mars Reconnaissance Orbiter
In addition, there is a hypothesis that suggests that not all of Mars’ first crust came from the magma ocean and had an origin different from basaltic. The Mars Reconnaissance Orbiter gathered data in the southern hemisphere, previously thought to be the planet’s oldest region. Payré and her research partners analyzed the data. They discovered nine locations – such as craters and fractures in the terrain – that had high concentrations of feldspar, a mineral associated with basaltic, rather than silicic, lava flows. Payré says that was the first clue. “It is because the terrains are feldspar-rich that we explored the silica concentrations there.”
Previously, feldspar had been discovered in other regions of Mars, but further analysis revealed that those areas were more basaltic in composition. A different instrument, called THEMIS, was turned to, which measures silica concentrations on the Martian surface through infrared wavelength reflections. A THEMIS analysis revealed that the terrain at the chosen locations was silicic rather than basaltic. Furthermore, it was found that meteorites like Erg Chech 002, discovered in the Sahara roughly at the creation of the solar system, exhibit similar silicic and other mineral compositions to the nine Martian locations studied by the team.
Moreover, researchers dated the crust to about 4.2 billion years ago, making it the oldest crust ever discovered on Mars. There are no remnants of Earth’s original crust left, as continental plates have been shifting for billions of years, and Mars’ crust is even more obscure, although we are beginning to understand it more. The study was published in Geophysical Research Letters.