UPDATED: NASA has created a stir in social networks in recent days when it announced a live conference on Monday morning, which would reveal a major scientific discovery on Mars.
The press conference, which took place a few minutes ago at the James Webb Auditorium at NASA Washington headquarters, was attended by Jim Green, NASA's director of planetary science, Michael Meyer, chief scientist for the Mars Exploration Program, Lujendra Ojha of the Georgia Institute of Technology, Mary Beth Wilhelm of the NASA Ames Research Center and the Georgia Institute of Technology, and Alfred McEwen, lead researcher for HiRISE (camera onboard the Mars Reconnaissance Orbiter that allows you to get high-resolution Mars images resolution) of the University of Arizona.
Horowitz crater was one of the places where signs of hydrated salts were observed
Water flowing on the red planet.
The agency confirmed that the "dark fingers" seen in Mars Reconnaissance Orbiter (MRO) imagery are probably made of liquid water moving across or below the planet's surface.
These marks, which lengthen and darken as the seasons change, are the first such evidence found on a planet other than Earth, and may be the first step in discovering Martian life.
Liquid Water Marks on Mars
First seen in 2011, the marks darkened on rocky slopes from late spring to early fall (as in the animation above).
By studying the infrared wavelengths of these streams, the researchers concluded that the marks were probably made by the flow of water due to the presence of hydrated salts.
This might even suggest that there is an ocean below the surface of the frozen desert of Mars.
We already knew that Mars had water in the past. This was well documented. But the fact that it still exists in a liquid state on the planet is a major scientific advance.
At the press conference, Michael Meyer of NASA's Jet Propulsion Laboratory said: “If we go back three million years and look at Mars, it was a very different atmosphere. The planet had a huge ocean, as large as two thirds of the Northern Hemisphere, more than a mile deep, but something happened. Mars has undergone major climate change and lost its surface water. Today we are revolutionizing our understanding of the planet. Mars is not the dry arid planet we thought, and under certain circumstances we can say that liquid water was found on Mars. ”
What we knew changed
Ice caps were discovered on the planet nearly four decades ago, and surface erosion patterns strongly suggested that rivers and oceans might have existed there. But we did not know that they could still exist.
With Mars's low gravity and thin atmosphere, scientists thought that this water had largely evaporated into space rather than falling back on the planet, as it does on Earth.
That is, Mars was considered a frozen desert. Evidence of flowing water changes everything that experts think they know about the planet and its ability to harbor life now.
In particular, finding definitive evidence of liquid water on Mars is an excellent indication that life may or may have existed on this planet.
In 2011, Lujendra Ojha “accidentally” discovered dark marks on Mars. Not only did they seem to move, they did so in a pattern consistent with running water.
On closer inspection, Lujendra noticed that the marks emerged in warmer seasons and disappeared during the colder ones. Thus, it investigated the composition of these seasonal flows by studying their infrared wavelengths.
In each of the studied sites, the presence of hydrated salts was found during the times when the flows were more extensive, suggesting a link between the two.
In particular, evidence has been found of sodium perchlorate, magnesium perchlorate and magnesium chloride.
The presence of perchlorate particularly suggests that water is salty rather than pure, and researchers believe that liquid water could be dissolving perchlorates in the soil before precipitating them back to higher concentrations.
If actually present on Mars, these salts would prevent water from freezing on the planet's surface, which means liquid water could remain.
This chart shows the distribution of the places where perchlorate salts were detected on Mars.
They can also form stable hydrated compounds and liquid solutions by absorbing water vapor from the atmosphere.
No direct evidence of these salts or liquid water was found - we do not have a sample - but the results strongly support the hypothesis of running water on Mars.
More studies will be done, for sure. However, as far as science is concerned, there are plenty of indications that liquid water exists on Mars.