Scientists working on Mars have a problem. Analysis of recent research results, delivered during the Rover “Curiosity” indicates that 3.5 billion years ago, the primitive atmosphere of the red Planet. too little carbon dioxide. The message, published in the journal “Proceedings of the National Academy of Sciences (PNAS)” cast doubt on existing theories of how Mars would have water in a liquid state.
/press releases
Scientists actually agree to the opinion that in the distant past on the surface of Mars had to swim the river that was there and the lake. The problem is that then the Sun shines intensively enough, on the surface of the red Planet could exist, respectively a high temperature. So I formed a theory, with a dense, CO2-rich atmosphere, due to the effect cieplarnianemu can keep the surface of the planet when the temperature is above zero.
This theory is now under question. Study the same rocks in which the probe Curiosity found when the settlement, which was to testify to the existence there of an ancient lake, now revealed that carbon dioxide there was too little. The Mars Rover found traces of carbonate, which in an atmosphere rich in CO2 should appear.
“the Lack of carbonate in the sample studied for Curiosity rocks sit down, surprised us,” says first author Thomas Bristow from Ames Research Center in Moffett field. “The presence of liquid water on the Martian surface would be unlikely, even if carbon dioxide was in the atmosphere a hundred times more than now seems possible.”
the Rover Curiosity using tool of CheMin for the chemical and mineralogical studies, have investigated numerous samples of rocks from the bottom of this hypothetical lake. The instrument allows him to detect even kilkuprocentową content of carbonate. None of the sample appeared. On this basis, the authors put the thesis of a maximum CO2 content.
In water carbon dioxide forms carbonates, associated with positively charged ions of magnesium and iron. Studies of other species of the lake bottom show that the ions were available, and the environment was never sufficiently acidic that carbonates could dissolve. If traces of the solution no, this must mean that carbon dioxide wasn’t enough.
/NASA
“This contradiction can be explained in two ways. Or we have not managed yet to develop climate models quite well describe the environment of Mars at the beginning of its existence, or actually deposits in the center of Gale crater was formed at low temperature,” says Alberto Fairén of the Centre for Astrobiology in Madrid. “The second possibility seems more likely”. According to him, in the area of Gale crater could remind the present Greenland and the frozen lake and the surrounding masses of ice.
the Search for carbonate on the surface of Mars was held for over two decades with spekrometrów installed on circling around the red Planet probes. These studies have not yielded the expected results. “The fact that was not observed solution of the orbit was a mystery to us,” says Bristow. “We tried to explain that maybe the carbonates, but not in the place where they are looking for, or sprinkled with dust. Research Curiosity made it possible to find them in the rocks that we know of that was created from underwater deposits”.
“the Findings from this analysis in terms of relevance of many theoretical studies, which indicated that the surface of Mars even really been warm enough that water could exist in liquid form,” adds co-author Robert Haberle from Ames Research Center in Moffett field. “There are opinions that, maybe, the lake was an open water reservoir that was covered with ice,” adds Haberle. “If the ice is not too thick, some sediment on the bottom can still occur”. This theory, too, however, has weaknesses. Curiosity Rover did not find in the center of Gale crater are typical of cracks and deposits, which was supposed to appear in the contact zone of the ice to the shore. The riddle remains unexplained.
Gregory Jasinski
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