The TGO orbiter of the European and Russian mission ExoMars discovered hydrogen chloride in the Martian atmosphere for the first time due to dust produced by the salty crust on its surface. It also provides unpublished information about the loss of water on the Red Planet from the relationship between the amount of hydrogen and deuterium.
Although two new ships arrived on Mars in February this year (Hope from the UAE and Tienwen-1 from China), Wanderer NASA’s “Perseverance” will do so on the 18th, and missions that have been operating there for many years will not stop sending relevant information about the Red Planet.
Two new discoveries of the team Mars alien, Published in several studies in the journal Scientific progress, Which provides new data on some of the main goals of exploring Mars: Atmospheric gas Related to biological or geological activities, and development water Determine the location of the past and present red planet to determine whether it is habitable and whether there is a reservoir for future manned missions.
Specifically, the TGO tool has detected Hydrogen chloride In the Martian atmosphere, and tracking how it loses water, reveals a brand new chemical substance and provides novel information about seasonal changes and interactions on the Martian surface.
“This is the first time we have discovered hydrogen chloride (HCl) on Mars. He pointed out that this is the first time that halogen gas (from the 7th group of the periodic table: fluorine, chlorine, bromine, etc.) has been detected in the Martian atmosphere, which represents An understandable new chemical cycle,” he pointed out. Kevin Olsen, From Oxford University (UK) and one of the leading scientists responsible for the discovery.
Hydrogen chloride (HCl), from A hydrogen atom and a chlorine atomIt is a sulfur and chlorine-based gas that igneous experts pay special attention to. It is an indicator of volcanic activity. However, the nature of the observation that the molecule was simultaneously detected at a very remote place points to another source, without the presence of other gases related to volcanic activity.
Martian dust storm
In this case, the findings indicate The interaction between the surface and the new atmosphere, Driven by the season of Mars and dust.
In a process very similar to that observed on Earth, the salt in the form of sodium chloride The remnants of the ancient ocean evaporate And embedded on the surface of Mars, they are blown into the atmosphere by the wind. Sunlight warms the atmosphere and causes dust and water vapor released from the pole cap to rise.
This The salty powder reacts with water in the atmosphere to release chlorineIt then reacts with hydrogen-containing molecules to produce hydrogen chloride. Therefore, we will be faced with a chemical scenario in which water plays a basic role and seems to be related to dust as well, because when the activity of dust increases, more hydrogen chloride is observed, which in turn is related to heating. Seasonal, especially in the southern hemisphere.
The team first detected natural gas simultaneously in the northern and southern hemispheres. Global sandstorms in 2018, And witnessed its rapid disappearance at the end of the seasonal sand and dust period. They are currently analyzing the data collected during the following sand and dust season, during which the increase in hydrogen chloride was again observed.
There may be a hydrogen chloride cycle on Mars. / That
“This is the first new type of natural gas discovered since it was observed. Methane The “Mars Express” program proposed by ESA in 2004 sought out other organic molecules and eventually promoted the development of the TGO mission. The main purpose of the TGO mission is to detect new gases. ” Håkan Svedhem, ESA ExoMars TGO project scientist.
Water vapor and climate change information
In addition to discovering new gases, TGO is also revolutionizing people’s understanding of gases. How does Mars lose water, This is also a process related to seasonal changes.
It is believed that liquid water has flowed across the surface of Mars in the past, Ancient valleys and rivers dry.Today, most of the water is Trapped in ice caps and underground. Today, however, Mars continues to lose water in the form of hydrogen and oxygen that escaped from the atmosphere.
Understanding the interrelationships between potential reservoirs and their seasonal and long-term behavior is critical to understanding the evolution of the Red Planet climate.
This can be achieved by studying water vapor and “half-heavy” water, where hydrogen (With protons and electrons) replaced by atoms deuterium (Also includes a neutron).
The ratio of deuterium to hydrogen works like a clock because it can tell the history of water on Mars and how the loss of water evolves over time.The ExoMars-TGO mission European Space Agency (ESA) and Russia’s Roscosmos Since the previous measurement only provided the average value of the entire atmosphere depth, you can observe the trajectory of different types of water as it rises in the atmosphere, which is unprecedented.
The ExoMars TGO orbiter observes water in the Martian atmosphere. Study water vapor and its composition as it rises through the atmosphere and enters space. By studying the relationship between hydrogen and its heavy metal deuterium, it is possible to track the passage of water over time. / That
The co-author said: “It seems that before we only had a two-dimensional view, but now we can explore the Martian atmosphere in 3D.” Ann Carine Vandaele, Researcher of BIRA-IASB Institute, Belgium, Head of Instrument NOMAD (found nadir and occultation) Was used in this research, and the Andalusian Institute of Astrophysics (IAA-CSIC).
The new data shows that once the water evaporates completely, it will show a large amount of semi-heavy water, and The ratio between deuterium and hydrogen is six times higher than that of the earth In all the sediments on Mars, it is confirmed that a large amount of water has been lost over time.
Three related phenomena
ExoMars data collected between April 2018 and April 2019 also showed three phenomena that accelerated the loss of water in the atmosphere: Planetary dust storm Of 2018 Short regional storm But in January 2019 and Discharge water from the bottle cap In summer, the amount of Antarctic ice changes with the seasons. It is particularly worth noting that the column of water vapor rising in the southern hemisphere in summer can inject water into the upper atmosphere seasonally every year.
Future observations coordinated with other ships, such as Marvin NASA’s research focuses on the upper atmosphere, which will provide supplementary data on the annual water evolution of Mars, and its meteorology will also study the Arab probe “Hope”.
“These two pieces of work prove the instrument that represents the Martian atmosphere: from the discovery and detection of hydrogen chloride, it was discovered that the content of hydrogen chloride was very small, but it was sufficient to be detected and quantified by the instrument. Norma Another feature called ACS is to characterize and quantify the water escaping from the planet, and even measure the proportion of heavy water escaping relative to the total amount. This is a very important step in understanding the evolutionary history of the Martian atmosphere, from a denser atmosphere to a large amount of water, to the weak atmosphere currently exhibited,” he concluded. Jose Juan Lopez Moreno, Is an IAA-CSIC researcher who participated in the results and the NOMAD instrument alliance.
O.Korablev et al. “Transient HCl in the Martian atmosphere“. Scientific progress, February 2021
G. Villanueva et al. “ExoMars / NOMAD reveals that water is severely fractionated as it rises on Mars.” Scientific progress, February 2021