Whereas slowly climbing the slopes of Mount Sharp — a towering peak inside Mars’ Gale Crater — NASA’s Curiosity rover made a exceptional discovery: giant deposits of carbon locked away in carbonate minerals. That will sound a bit dry at first, however in actuality this discover might be a serious piece of the puzzle in our seek for historical life on the Crimson Planet.
Carbonate minerals type when carbon dioxide interacts with water and rock, making them an vital marker of previous environmental situations. Scientists have noticed these minerals earlier than on Mars — by rovers on the bottom, orbiters above, and even in Martian meteorites that fell to Earth — however Curiosity’s newest knowledge provides thrilling new particulars.
“It tells us that the planet was liveable and that the fashions for habitability are appropriate,” stated the research’s lead writer, Ben Tutolo, affiliate professor with the Division of Earth, Vitality and Surroundings within the College of Science on the College of Calgary, in a statement.
The minerals discovered by the rover seemingly shaped in extraordinarily dry situations via chemical reactions between water and rock adopted by the method of evaporation. This course of factors to a time when Mars had a thick sufficient ambiance, wealthy in carbon dioxide, to assist liquid water on the floor. Nonetheless, because the ambiance thinned, that carbon dioxide would have begun turning into stone.
One standout mineral in Curiosity’s new discovery is siderite, an iron-rich carbonate present in surprisingly excessive quantities — between 5 and 10% by weight — alongside salts that dissolve simply in water. “The broader implications are the planet was liveable up till this time, however then, because the [carbon dioxide] that had been warming the planet began to precipitate as siderite, it seemingly impacted Mars’ capability to remain heat,” stated Tutolo.
What makes this discover much more fascinating is the presence of iron oxyhydroxides in the identical deposits. These minerals counsel Mars could have as soon as additionally had a functioning carbon cycle — just like Earth’s — the place a number of the carbon dioxide locked in rocks finally made its manner again into the ambiance.
By evaluating Curiosity’s findings with orbital knowledge, scientists consider comparable layers throughout the planet may have trapped as much as 36 millibars’ price of atmospheric carbon dioxide — sufficient to dramatically change Mars’ local weather.
This Martian discovery additionally ties in carefully with work being executed proper right here on Earth. Tutolo says he is been exploring methods to fight local weather change by turning human-made carbon dioxide into secure carbonate minerals — basically locking carbon away in rock.
“What we’re attempting to do on Earth to battle local weather change is one thing that nature could have already executed on Mars,” he stated. “Studying concerning the mechanisms of creating these minerals on Mars helps us to raised perceive how we will do it right here. Finding out the collapse of Mars’ heat and moist early days additionally tells us that habitability is a really fragile factor.”
