Mars has water, but this water is apparently found only in the icy caps of the Red Planet poles or in the form of gas in its atmosphere. Water has been escaping from the planet for billions of years since Mars lost its magnetic field and much of its climate. Now two new studies have shown how water moves in and out of the Red Planet’s atmosphere.
The two studies were conducted by Anna Fedorova, a researcher at the Russian Academy of Sciences Space Research Institute, and Jean-Yves Chaffrey, a scientist at LATMOS Laboratory in France. done, Used data from the European Space Agency’s ExoMars and Mars Express orbiters to show that the rate at which Mars’ water escapes changes as the planet changes its climate, climate and distance from the Sun.
“The atmosphere is the link between the planet’s surface and space, so it can tell us a lot about how Mars lost its waters,” Fedorova said in a statement. Researchers in both studies used ExoMars special spectrometer data called SPICAM, which is used to observe the Martian atmosphere.
“We studied atmospheric water vapor from the surface to an altitude of 100 km,” explains Fedorova. Scientists have found that when Mars is at its greatest distance from the Sun (400 million kilometers), water vapor in the atmosphere is found only at altitudes of less than 60 kilometers. But when the planet reaches the closest distance from the sun (ie 333 million kilometers), water is also visible at a distance of 90 kilometers.
When Mars and the Sun are far apart, the cold freezes the water vapor in the atmosphere, but as the distance decreases and the temperature increases, water can circulate more. Because water vapor can enter the Martian atmosphere more during the warmer seasons, it is at these times that the red planet loses more water.
Fedorova adds: “The upper atmosphere is humid and saturated with water, which is why water is leaving the planet faster this season; “Water rises, so it escapes into space more easily.”
But different seasons are not the only factor that increases or decreases the escape of water into space. Dust storms also play an important role. Examining data from an eight-year period, the researchers say that during the years when Mars suffered from total dust storms, the water in the Martian atmosphere rose higher. During these years, scientists have been able to find water vapor at a distance of 80 km from the planet. They have found that Mars loses two meters of water every billion years.
“This confirms that dust storms that disrupt and warm the Martian atmosphere are pushing water to higher altitudes,” Fedorova said. “With the help of Mars Express continuous observations, we were able to analyze two global dust storms on Mars in 2007 and 2018 and compare our findings with available data from storm-free years to see how these storms affected the outflow of water from Mars.”
However, we still cannot fully explain the amount of water lost by Mars in the last 4 billion years. “To explain the water features of Mars, there must have been a lot of water on the planet at one time,” says Chaffrey. “Because all this water has not been lost in space, our results show that either this water has gone below the surface of Mars or the escape rate of water has been much higher in the past.”