Curiosity Rover Finds Hints of a Carbon Cycle on Ancient Mars (arstechnica.com) 11
Billions of years ago Mars "had a warm, habitable climate with liquid water in lakes and flowing rivers," writes Ars Technica.
But "In order for Mars to be warm enough to host liquid water, there must have been a lot of carbon dioxide in the atmosphere," says Benjamin Tutolo, a researcher at the University of Calgary. "The question we've been asking for at least 30 years was where the record of all this carbon is." Tutolo led a new study of rock samples collected by the Curiosity rover that might have answered this question...
Curiosity rover was called Mars Science Laboratory for a reason. It went to the red planet fitted with a suite of instruments, some of which even the newer Perseverance was lacking. These enabled it to analyze the collected Martian rocks on the spot and beam the results back to Earth. "To get the most bang for the buck, NASA decided to send it to the place on Mars called the Gale Crater, because it was the tallest stack of sediments on the planet," Tutolo says. The central peak of Gale Crater was about 5 kilometers tall, created by the ancient meteorite impact... The idea then was to climb up Mount Sharp and collect samples from later and later geological periods at increasing elevations, tracing the history of habitability and the great drying up of Mars.
On the way, the carbon missed by the satellites was finally found...
It turned out the samples contained roughly between 5 and 10 percent of siderite... The siderite found in the samples was also pure, which Tutolo thinks indicates it has formed through an evaporation process akin to what we see in evaporated lakes on Earth. This, in turn, was the first evidence we've found of the ancient Martian carbon cycle. "Now we have evidence that confirms the models," Tutolo claims. The carbon from the atmosphere was being sequestered in the rocks on Mars just as it is on Earth. The problem was, unlike on Earth, it couldn't get out of these rocks... A large portion of carbon that got trapped in Martian rocks stayed in those rocks forever, thinning out the atmosphere.
"While it's likely the red planet had its own carbon cycle, it was an imperfect one that eventually turned it into the lifeless desert it is today," the article points out.
But the study still doesn't entirely explain what warmed the atmosphere of Mars — or why Martian habitability "was seemingly intermittent and fluctuating".
But "In order for Mars to be warm enough to host liquid water, there must have been a lot of carbon dioxide in the atmosphere," says Benjamin Tutolo, a researcher at the University of Calgary. "The question we've been asking for at least 30 years was where the record of all this carbon is." Tutolo led a new study of rock samples collected by the Curiosity rover that might have answered this question...
Curiosity rover was called Mars Science Laboratory for a reason. It went to the red planet fitted with a suite of instruments, some of which even the newer Perseverance was lacking. These enabled it to analyze the collected Martian rocks on the spot and beam the results back to Earth. "To get the most bang for the buck, NASA decided to send it to the place on Mars called the Gale Crater, because it was the tallest stack of sediments on the planet," Tutolo says. The central peak of Gale Crater was about 5 kilometers tall, created by the ancient meteorite impact... The idea then was to climb up Mount Sharp and collect samples from later and later geological periods at increasing elevations, tracing the history of habitability and the great drying up of Mars.
On the way, the carbon missed by the satellites was finally found...
It turned out the samples contained roughly between 5 and 10 percent of siderite... The siderite found in the samples was also pure, which Tutolo thinks indicates it has formed through an evaporation process akin to what we see in evaporated lakes on Earth. This, in turn, was the first evidence we've found of the ancient Martian carbon cycle. "Now we have evidence that confirms the models," Tutolo claims. The carbon from the atmosphere was being sequestered in the rocks on Mars just as it is on Earth. The problem was, unlike on Earth, it couldn't get out of these rocks... A large portion of carbon that got trapped in Martian rocks stayed in those rocks forever, thinning out the atmosphere.
"While it's likely the red planet had its own carbon cycle, it was an imperfect one that eventually turned it into the lifeless desert it is today," the article points out.
But the study still doesn't entirely explain what warmed the atmosphere of Mars — or why Martian habitability "was seemingly intermittent and fluctuating".
Cycle on Mars RAH (Score:2)
In Space Family Stone the twins Castor and Pollux transport bicycles from Luna to Mars.
AKA The Rolling Stones
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But my dog will chase them in either place [gifdb.com].
Ionization theory? (Score:1)
I thought the leading theory was that the atmosphere got ionized out into space because Mars lost its magnetosphere when its core cooled.
How much got trapped in rocks versus ionized away?
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Martian atmosphere - whatever's left of it anyway - is almost entirely CO2.
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Okay, but why did the ionization theory fall out of favor? It's long been known that Mars is no longer volcanically active in a general sense and probably hasn't been for a good while.
(As somebody pointed out, Mars does have a weak magnetic field, but it's very very weak, probably not good at stopping ionization leaking.)
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That was a leading hypothesis long ago.
For starters: Mars still has a magnetic field. Albeit weak.
Most of the atmosphere was absorbed by "rocks". At least that is the current working hypothesis. And foundation for "making" oxygen on mars. As regolith has a high percentage of bound oxygen (and other gases) that can be released by heat. Works even on the Moon.
The problems/questions on what actually happened is many fold. I mean to put kind of hard to put probabilities on it.
- How long ago did Mars more or les
So still no signs of life that might have lived... (Score:3)