New research suggests that the atmosphere on Mars is hiding in plain sight, as it is made up of minerals in the Red Planet’s clay. If the gas envelope of Mars “went down” more than 3 billion years ago, this could explain how Earth’s neighboring planet became so different from our Earth, which is a possibility that it loses its ability to receive life.
Scientists know that the Red Earth was not always the dry and arid place that Mars is today. Two NASA robots have discovered evidence that large amounts of water flowed on Mars early in its 4.6 billion year history. But in order for Mars to have liquid water, it must have also had an atmosphere that prevents this water from becoming ice. The big question for decades has been: where did this spaceship go when it disappeared?
A team of researchers think the answer has been under the noses (or paths) of Curiosity and Patience all along. In a paper published in Science Advances, they argue that although water did exist on the Red Planet, it may have flowed through certain types of rock and started a small series of actions that removed carbon dioxide from the atmosphere. This would then have been converted into methane, another form of carbon, and locked up in the Martian soil.
“Based on what we found on Earth, we show that a similar process might be at work on Mars and that a lot of atmospheric carbon dioxide would have been converted to methane and sequestered in clay,” the member of the group Oliver Jagoutz, a professor of geology at the Massachusetts Institute of. The Department of Earth, Atmospheric and Planetary Sciences (MIT EAPS), said in a statement. “This methane could still exist and possibly be used as an energy source on Mars in the future.”
Related: NASA’s Perseverance Mars rover is about to conduct the 1st crater rim study ‘Dox Castle’.
How Earth gave way to the atmosphere of Mars
Working in his MIT group, Jagoutz and his colleagues did not start their research with Mars but with our planet. Scientists were trying to figure out what geological processes drive the change in the Earth’s hard but brittle layer that covers the surface and mantle, and is known as the lithosphere.
The researchers focused on a type of surface clay mineral called “smectite,” which is very effective at sequestering carbon. A single smectite seed is made up of many folds of carbon that can sit and stay in it for billions of years without moving or being disturbed.
On Earth, smectites are formed by the movement of tectonic plates on which the continents sit. This tectonic event also raised smectites to the surface of our planet. When this clay mineral was on the surface of the water it absorbed carbon dioxide, removing this greenhouse gas and helping our planet to rest for millions of years.
The team turned their attention to Mars when Jagoutz looked at the Red Planet’s surface, and saw smectite-like material scattered throughout Earth’s neighborhood.
The discovery of smectites on Mars raised an important question: Since the Red Planet lacks tectonic activity, how did these folded clay minerals form? To answer this question, the team turned to what they know about the geological history of Earth’s neighbor.
Another factor was the detection of rocks with low silica in the upper part of the Red Planet called “ultramafic rocks.” On Earth, these igneous rocks are known to form smectites when they are weathered or “weathered” by water. On Mars, there is evidence of ancient rivers where water could have flowed and reacted with the rock below.
The team then used knowledge of the interaction of water and hot rocks on Earth to create a model that could be used on Mars. The model would reveal if water would have reacted with the deep Martian ultramafic rocks in a way that would produce the smectites on the surface today.
Using this model, scientists discovered that over a period of billions of years, water would have penetrated the surface to react with a magnesium silicate mineral rich in igneous rock called ” olivine.” This mineral is rich in iron, which the oxygen in the water would bind to as it evolved, releasing hydrogen. This oxygen-rich metal may have helped give Mars its distinctive red color.
The released hydrogen would then combine with the carbon dioxide in the water to form methane, and this reaction slowly turns the olivine into another metal-rich rock called serpentine. As the snake continued to react with water, this would have eventually formed smectites.
“These smectite clays have a lot of carbon storage capacity,” lead author of the study and MIT EAPS graduate student Joshua Murray said in the statement. We then used the existing knowledge of how these minerals are stored in clay on Earth, and extrapolated to say, if the Martian area has this much clay, how much methane can it store? in that clay?
The team found that to maintain the amount of methane needed to remove more carbon dioxide from the Martian atmosphere, the Red Planet would have to be covered in a layer of smectite 1,100 meters deep.
Murray concluded: “We find that estimates of global clay abundances on Mars are consistent with a large fraction of early Martian carbon dioxide thought to be organic compounds in the surface. which has a lot of clay. “In some ways, Mars’ missing atmosphere may be hiding in plain sight.”
The team’s research was published Sept. 25 in the journal Science Advances.
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