NASA scientists have identified the main cause of changes in the atmosphere of Mars

Photo: NASA / GSFC

NASA stated that its specialists working in the Mars Atmosphere and Volatile Evolution project (MAVEN) were able to identify a process that plays a major role in changing the climate of Mars from warm and humid (by the way, there is an assumption that warm and humid Mars since there has never been) dry and cold.

The data provided by MAVEN allowed the researchers to determine the rate of loss of the atmosphere by the Red Planet under the influence of the solar wind. Scientists also found that speed increases, and very significantly, during solar storms. The research results were published in the journals Science and Geophysical Research Letters on November 5th.

“Mars had previously had a rather thick and warm atmosphere for water to exist in liquid form, this is a key element of life, as we believe now,” says John Groussfeld, an astronaut and a representative of NASA Science Mission Directorate. “Understanding what happened to the atmosphere of Mars will allow us to understand the dynamics and evolution of the gas shell of the Red Planet. Understanding what can trigger changes in conditions from those that can support life to those that are not able to do this is a key issue, ”continued Gransfeld.
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Spacecraft MAVEN

MAVEN data show that the solar wind carries about 100 grams of atmospheric gas into space every second. Over time, the changes become very significant. At the same time, during solar storms, the rate of atmospheric escape to space increases significantly. Based on this, scientists conclude that when the Sun was more active (billions of years ago), the planet’s rate of atmospheric loss was much higher than it is now.

The conclusion about the acceleration of the loss of the atmosphere by Mars was made after analyzing the data MAVEN, relating to March 2015. Then several storms happened on the Sun at once, and the device recorded a significant increase in the rate of gas escape into space.

Solar wind (English Solar wind) - a stream of megaionized particles (mainly helium-hydrogen plasma) flowing from the solar corona at a speed of 300-1200 km / s into the surrounding space. It is one of the main components of the interplanetary medium.

MAVEN was able to determine how the solar wind and ultraviolet radiation carried gas from the upper layers of the Martian atmosphere into open space. New results show that losses are mainly in three different regions of the Red Planet: in the “tail”, behind Mars, over the Martian poles and in the expanded gas cloud surrounding Mars. About 75% of the outgoing ions lose their “tail”, about 25% lose their poles, and only a little (a fraction of a percent) are lost in the third region.

In some regions of Mars there are clear signs of once-existing liquid water. This allowed scientists to conclude that once water really flowed over the surface of the planet, and this is possible only under the condition of a warm climate and a thick atmosphere.

Interestingly, NASA has a group of scientists who believe that Mars has never been particularly warm and humid . These experts argue that even if the atmosphere of Mars was indeed much more dense than it is now, most of it was lost by the time of the formation of the network of valleys and rivers. At that time, the atmosphere was still dense enough to maintain the existence of liquid water, but this era cannot be called warm. Most likely, most of Mars was not covered with lakes at all, but with ice, with occasional snowfall instead of rain. And with a slight increase in temperature, this ice melted, with the subsequent appearance of a large amount of liquid water forming the valleys. After a while, all this could freeze again.