Where liquid water on Mars comes from? Scientists in a quandary
Researchers agree that rivers and lakes existed on the Red Planet in the past. However, data from the Martian rover showed a lower-than-expected amount of CO2 on Mars, which would not keep the water liquid.
According to data sent by the Curiosity rover, in the past there was not enough CO2 on Mars to cause a greenhouse effect, whichóry móheads to keep the temperature above zero, which in turn would allow liquid water to occur.
3.5 billion years ago, the Sun was less active than it is today and, according to experts, was unable to sufficiently heat the surface of the Red Planet. This is why they formulated a theory about the greenhouse effect on Mars.
In the analysis of rocks examined by Curiosity, there is not a trace of carbonateów whichóre should occur if Mars had a carbon dioxide-rich atmosphere in the past. The rover studied próbki of rocks in the place whereórym, according to scientistsów, long ago there was a lake.
CO2 in water forms carbonates. It binds to positively charged magnesium and iron ions. However, the rover’s instruments, did not show the presence of carbonateów. It should be noted that Curiosity’s instruments are sensitive enough to detect even trace amounts of them.
– What struck us most was precisely the lack of carbonateóIn the sedimentary rocks studied by Curiosity. In such a situation, the presence of liquid water on the surface of the Red Planet would be unlikely, even if there was a hundred times more carbon dioxide in the atmosphere than the evidence suggests – said Thomas Bristow of the Ames Research Center at Moffett Field.
– This has been a mystery to us for a long time. From Martian orbit, we haven’t seen much carbonateów. We explained that, they are covered with dust, they are under the surface or we are not looking in the right place. The results obtained by Curiosity directly on the surface give new impetus to this Martian paradox – Bristow further explained.
Scientists prób to explain this paradox. – This contradiction can be explained in two ways. Either we have not yet been able to develop climate models sufficiently describing the Martian environment at the beginning of its existence, or the sediments studied by the rover were formed at low temperatures, Alberto Fair saidén from the Center for Astrobiology in Madrid, który also participated in the study.
The results of the analysis were published in the Proceedings of the National Academy of Science.