Our beloved red planet has a desert appearance, but it hides large quantities of frozen water under its surface. That water continues to escape from Mars and, interestingly, dust storms play a very important role in this.
1 - Two 2001 images of the Mars Orbiter Camera on NASA's Mars Global Surveyor orbiter show a dramatic change in the planet's appearance when the haze lifted by dust storm activity in the south was globally distributed. Credits: NASA / JPL-Caltech / MSSS
A paper recently published, to be more precise on January 22, 2018. Entitled "Hydrogen escape from Mars enhanced by deep convection in dust storms", it shows that the loss of water from Mars has not stopped but continues inexorably. Perpetuating the desert image of the surface of our neighbor red planet.
”Present-day water loss from Mars provides insight into Mars’s past habitability. Its main mechanism is thought to be Jeans escape of a steady hydrogen reservoir sourced from odd-oxygen reactions with near-surface water vapour.”
Q1 - Nature - doi:10.1038/s41550-017-0353-4, 2018
In order to carry out this study, scientists have studied the data of the Mars Climate Sounder. One of the scientific tools aboard the Mars Reconnaissance Orbiter. The probe that has been orbiting Mars since 2006. Thanks to the MCS, we now know much more about the key properties of the atmosphere of Mars. Of its composition and its chemical interactions at different altitudes.
2 - Artist's concept of the Mars Reconnaissance Orbiter at Mars features one of its instruments - the Mars Climate Sounder - in action. Credits: NASA /JPL
Previously it had been predicted that the flow of ultraviolet radiation from the sun was the one that modulated the escape of hydrogen. But thanks to the study of the data of the MCS, scientists have been able to observe that the correlation between ultraviolet radiation and the escape of hydrogen is very poor. They have also found that there is a large seasonal variability in the observed escape rate.
After collecting data for more than ten years these are some of the results obtained by scientists:
”Here, we report multi-annual observational estimates of water content and dust and water transport to the middle atmosphere from Mars Climate Sounder data. We provide strong evidence that the transport of water vapour and ice to the middle atmosphere by deep convection in Martian dust storms can enhance hydrogen escape. Planet-encircling dust storms can raise the effective hygropause (where water content rapidly decreases to effectively zero) from 50 to 80 km above the areoid (the reference equipotential surface).”
Q2 - Nature - doi:10.1038/s41550-017-0353-4, 2018
3 - Photograph of Crisp Crater in Sirenum Fossae taken by the MRO. Credits: NASA/JPL-CALTECH/UNIVERSITY OF ARIZONA
Although many of the phenomena that occur in the Martian atmosphere, chemical exchanges, interactions with solar winds and the radiation that comes from the outskirts of our solar system are still unknown. This new paper comes to provide a little more knowledge about what happens on the surface of the red planet.
”Our results imply that Martian atmospheric chemistry and evolution can be strongly affected by the meteorology of the lower and middle atmosphere of Mars.”
Q3 - Nature - doi:10.1038/s41550-017-0353-4, 2018
Understanding the processes that occur in the Martian atmosphere will be of vital importance for future manned trips. Especially if at some point in the future human beings intend to create permanent settlements there. Studying the data that continues to collect the Mars Reconnaissance Orbiter (MRO), will allow us to have a good database large enough to see the subtle variations in the composition of the atmosphere of Mars through the years.
References
Q1, Q2, Q3, - “Hydrogen escape from Mars enhanced by deep convection in dust storms”. N. G. Heavens et al. Nature Astronomy 2 - doi:10.1038/s41550-017-0353-4, 126-132 (2018)
https://www.nature.com/articles/s41550-017-0353-4
1 - Global Dust Storm - MGS - NASA
https://mars.nasa.gov/resources/21448/
2 - MRO - NASA
https://www.nasa.gov/mission_pages/MRO/multimedia/Climate-Sounder.html
3 - Crater picture - MRO - NASA
https://marsmobile.jpl.nasa.gov/mro/multimedia/images/
