A 2015 image shows a trail of lines called 'seasonal ramps' that scientists think might have been formed by salt water flow, but the latest findings disagree
SAN FRANCISCO, Nov. 24 news, according to foreign media reports, in 2015, NASA held a special conference to announce the discovery of 'the most powerful evidence so far' to prove that there is still liquid water flowing on Mars. Dark streaks that appear seasonally on some slopes.
Jim Green, director of NASA's planetary sciences, was also on the scene envisioning some future astronauts using the liquid water on Mars to get access to water after they landed on Mars.
At the time, he said: 'Matt Watney in Mars Rescue will know this discovery,' and a large percentage of scientists think these flowing liquid water may mean the presence of microbes.
Then, scientists at the US Federal Geological Survey, who are known as 'The Destroyer of Dreams,' decided to study the finding, and on Monday they published a paper in which they pointed out that those darker Stripes are not the traces of liquid water at all, but merely traces of the flow of sand or dust.
Colin Dundas, the lead author of the study, said: 'This study supports the view that today's Mars is very dry.'
The discovery disappoints many people, who have been hoping for the dark stripes, or strictly speaking, the so-called 'seasonal ramp' (RSL) as evidence of true liquid water, because that would mean that Mars is not completely barren.
Although the RSL itself is not directly evidence of the presence of liquid water, it is indeed strong enough indirect evidence that scientists noticed that these streaks appear and disappear as the season changes, just as the salt water is melted by the sun's heat and follows Not only that, scientists also identified perchlorate in these streaks, and the presence of this substance lowers the condensation point of the water and keeps it liquid over a wider temperature range .
But Gordon and his colleagues studied the RSL case images previously shot and found that the traces did not correspond to the characteristics of flowing bodies of water and, to put it simply, they seemed to exist only at the top of steep slopes; Also, the RSL ends here once the slope reaches the angle of repose, which is the lowest angle at which the slope material will stay intact without slippage.
If you've ever tried to build a sand castle, you'll know the concepts above, which is why drier sand (shallow repose) is easier to slip and wetter sand (with a steeper angle of repose) But heap can be higher.
Alfred McEwen, a co-author and author at the University of Arizona, said: "RSLs never reach gentle slopes, and their correlations with the power angle of repose are great. We do not think This is a coincidence. "Mike Owen is the chief scientist of HiRISE onboard the Mars Reconnaissance Orbiter (MRO).
So their point of view is that the RSLs are not formed by the body of water, and rather they behave much like tiny sand falling down from above.
However, they also cautioned that this finding does not mean that the RSL has nothing to do with water, such as the appearance of these traces appear to be related to seasonal changes, combined with hypochlorite, or the presence of moisture contribute to these traces But no matter how, even if water really exists, then the water must also be very, very small.
This finding is also consistent with the view of a paper published last year in the Geophysical Research Bulletin that at the time this article considered the water content in the RSL not to exceed 3%, which is almost equivalent to moist sand, or Say, some salt water in the sand.
Perhaps the dark stripes on Mars do not contain enough water for astronauts to take advantage of and may not be the home of micro-organisms, but they still deserve our exploration and research.
Mike Owen said: "Perhaps the RSL is formed in a special mechanism that exists only in the Mars environment so it will provide an opportunity for us to understand how the Mars environment will function and that will be important for future exploration."