It was a mirage .. a new study denies the existence of liquid water on Mars
Is there liquid water under the surface of Mars, as confirmed by previous scientific research? According to a new scientific study, liquid water discovered a few years ago under the south pole of Mars covered in ice may be just a “mirage”. This discovery raises again the debate among scientists about the question of whether or not there is water under the surface of the Red Planet.
In 2018, scientists believed – after analyzing the reflections of radar waves on the outer layers under the polar cover of Mars – that they had discovered the presence of liquid water there, and this discovery was questioned by a wide range of scientists, because the cold and dry conditions in that region were not suitable for the presence of water in liquid state.
More reasonable explanation
and in The new study Published recently in the journal “Geophysical Research Letters”, researchers from the University of Texas at Austin and the French Grenoble Alps found that the radar reflections that researchers adopted 4 years ago to confirm the presence of water coincide with those that occur on the volcanic plains on the surface of the Red Planet .
Researchers believe -according to press release It was published on the University of Texas website on January 24 that their latest conclusion provides a more reasonable explanation than the hypothesis that liquid water exists in those conditions that do not allow it to form.
“Liquid water near the surface of Mars requires a highly saline environment, a strong heat source, and a local generator, but this does not match what we know about this region,” says Cyril Grima, a planetary scientist at the University of Texas and lead author of the study.
To reach these results, the authors of the new study used data collected over a period of 3 years, the “Marsis” radar device installed on the “Mars Express” probe, which was launched by the European Space Agency in 2005.
The results of simulations of the reflection of radar waves on surfaces of different components showed that the “mirage” on which scientists built the hypothesis of the presence of liquid water under the south pole of Mars vanishes when an imaginary ice sheet is added in a radar map of the entire surface of Mars.
Grima and her team observed bright reflections, just like those seen in Antarctica but scattered across all latitudes and matching the locations of the volcanic plains on the Red Planet.
These bright reflections of radar waves are known to scientists on Earth, where iron-rich lava flows can leave rocks that reflect these waves in a similar way.
The bright radar signals may indicate the presence of a type of mud that forms when rocks erode in the water, believes Isaac Smith, a Mars geophysicist at York University, according to the same source.
Smith, who was not involved in the latest study, had found in 2021 that ground mud reflects radar waves brightly, just like the bright spots in the 2018 Antarctic study. In addition, other possible possibilities also include mineral deposits in dry riverbeds.
The past is wetter
Although the new study shows that liquid water may not be present under the south polar cap of Mars, it indicates – in contrast – that there is a lot of water ice on Mars, including in the thick polar summits, and that Mars’ past was wetter than now. .
It also gives scientists precise places to look for evidence of ancient lakes and river basins and to test hypotheses about how a gradually dry climate dominated Mars over billions of years.
Despite these disappointing results regarding the presence of liquid water on Mars, the study authors are now working on new missions to find water there using radar, with the aim of identifying future human landing sites, and searching for signs of past life.