Mars, the fourth planet farthest from the Sun, has been the object of close attention of world science for a long time. This planet is very similar to the Earth with one small but fateful exception - the atmosphere of Mars is no more than one percent of the volume of the earth's atmosphere. The gas envelope of any planet is the determining factor that shapes its appearance and conditions on the surface. It is known that all the solid worlds of the solar system were formed under approximately the same conditions at a distance of 240 million kilometers from the Sun. If the conditions for the formation of Earth and Mars were almost the same, then why are these planets so different now?
It's all about the size - Mars, formed from the same material as the Earth, once had a liquid and hot metal core, like our planet. Proof - a lot of extinct volcanoes on the surface of Mars. But the "red planet" is much smaller than the Earth. Which means it cools down faster. When the liquid core finally cooled down and solidified,the process of convection ended, and with it the magnetic shield of the planet, the magnetosphere, also disappeared. As a result, the planet remained defenseless against the destructive energy of the Sun, and the atmosphere of Mars was almost completely blown away by the solar wind (a giant stream of radioactive ionized particles). The "Red Planet" has become a lifeless, dull desert…
Now the atmosphere on Mars is a thin, rarefied gaseous shell, unable to withstand the penetration of deadly solar radiation, which burns the surface of the planet. The thermal relaxation of Mars is several orders of magnitude smaller than that of Venus, for example, whose atmosphere is much denser. The atmosphere of Mars, which has a too low heat capacity, forms more pronounced daily average wind speed indicators.
The composition of the atmosphere of Mars is characterized by a very high content of carbon dioxide (95%). The atmosphere also contains nitrogen (about 2.7%), argon (about 1.6%) and a small amount of oxygen (no more than 0.13%). The atmospheric pressure of Mars is 160 times higher than that at the surface of the planet. Unlike the Earth's atmosphere, the gaseous envelope here is highly variable, due to the fact that the polar caps of the planet, containing a huge amount of carbon dioxide, melt and freeze during one annual cycle.
According to data received from the Mars Express research spacecraft, the atmosphere of Marscontains some methane. The peculiarity of this gas is its rapid decomposition. This means that somewhere on the planet there must be a source of replenishment of methane. There can be only two options here - either geological activity, traces of which have not yet been discovered, or the vital activity of microorganisms, which can turn our understanding of the existence of centers of life in the solar system.
A characteristic effect of the Martian atmosphere is dust storms that can rage for months. This dense air blanket of the planet consists mainly of carbon dioxide with minor inclusions of oxygen and water vapor. Such a lingering effect is due to the extremely low gravity of Mars, which allows even a super-rarefied atmosphere to lift billions of tons of dust from the surface and hold for a long time.
