Mars Mystery Solved? MIT May Have Found Its Lost Atmosphere

Mars has fascinated mankind for much of its history. Unusually and distinctively red even when viewed with the naked eye, it was watched as it traced its unusual path across the sky by the great lost civilizations of old.

Both the ancient Egyptians and ancient Chinese have records of Mars in their astronomical notes. The Babylonians calculated how to predict where it would be in the sky, and the Greeks tied themselves in knots trying to explain how it moved if (as was obvious to them) the Earth was at the center of the universe.

Our understanding of the planet only became sharper when Galileo Galilei first pointed a telescope at Mars in 1610, uncovering a wealth of strange and unexplained features on the surface. Chief among these features are probably the Martian “canals” which were thought to be artificial: for much of our recent past we believed with sincerity that there was life out there, another alien intellect looking back at us.

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But now we are fairly sure that Mars is a dead planet, at least on the surface. What little atmosphere it has is thin and unable to sustain life as we know it, and our repeated robotic trips there have so far only confirmed this assessment.

But in this we face a mystery. There is plenty of evidence in the geology that Mars was not always this cold and dead: there was once running water on the surface and a dense carbon dioxide atmosphere.

Something happened around 3.5 billion years ago which caused the atmosphere to disappear and the water to dry up. And, in a new paper published last month in Science Advances, researchers think they have found the solution to where this atmosphere went.

In the paper, MIT scientists modelled the effect of water reacting chemically with the surface geology, specifically what they call “ultramafic rocks” which are abundant in the surface layer of Mars. 

These Marian surface clays formed during Mars’s early geologic period, are thought to have absorbed up to 80% of Mars’s atmospheric carbon in the process known as “abiotic methanogenesis” which essentially means “turned into methane in a process which doesn’t involve life.”

This methane can be stable for millions of years, and there is increasing evidence of carbon stored in the crust which points to this being the truth. So far, so research paper, and a good question should be why anyone would get excited about a lifeless process on a dead planet.

Well, aside from the fact that we know something new about a planet millions of kilometers away and billions of years in the past, this trapped carbon may be extremely useful to anyone who wants to visit the red planet in the future. Specifically, the carbon dioxide could again be released from the methane, and used as an energy source for longer term space missions.

Put simply, this might mean that the surface of Mars is, through a geological process a billion years in the making, covered in a fuel source for our interplanetary craft. Mars could become a staging post for subsequent missions, both within the Solar System and out into the depths of space beyond.

There are other, loftier possibilities offered by this research as well. Such trapped carbon could be extremely useful for any attempts to terraform the planet and transform Mars into a planet with a breathable atmosphere. And while such dreams are firmly in the realms of fiction at this point, it seems that another piece of the puzzle may just have fallen into place.

Header Image: The thin remnant atmosphere that currently covers the red planet. Researchers at MIT have now found out what happened to the carbon dioxide atmosphere that once covered Mars. Source: NASA / Public Domain.