Mars, the fourth planet remotely from the Sun,has long been an object of close attention to world science. This planet is very similar to Earth after one, small, but fateful, exception - the atmosphere of Mars is not more than one percent of the volume of the Earth's atmosphere. The gas envelope of any planet is the determining factor shaping its appearance and conditions on the surface. It is known that all the solid worlds of the solar system formed approximately in the same conditions at a distance of 240 million kilometers from the Sun. If the conditions for the formation of the Earth and Mars were practically the same, then why are these planets so different now?
It's all about size - Mars formed fromthe same material as the Earth, had once a liquid and hot metal core, like our planet. Proof is a set of extinct volcanoes on the surface of Mars. But the "red planet" is much smaller than the Earth. So, it cooled faster. When the liquid core finally cooled and solidified, the convection process was completed, and with it the magnetic shield of the planet, the magnetosphere, disappeared. As a consequence, the planet remained defenseless before the destructive energy of the Sun, and the atmosphere of Mars was almost completely blown away by the solar wind (a gigantic stream of radioactive ionized particles). "Red Planet" has become a lifeless desolate desert ...
Now the atmosphere on Mars is aa thin discharged gas 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 the similar index, for example, of Venus, whose atmosphere is much denser. The atmosphere of Mars, which has too little heat capacity, forms more pronounced daily average wind speed.
The composition of the atmosphere of Mars is characterized by a veryhigh content of carbon dioxide (95%). Also, the atmosphere contains nitrogen (about 2.7%), argon (about 1.6%) and a small amount of oxygen (not more than 0.13%). The atmospheric pressure of Mars is 160 times higher than that of the planet's surface. Unlike the terrestrial atmosphere, the gas shell here is of a pronounced volatile nature, due to the fact that the polar caps of the planet, containing a huge amount of carbon dioxide, melt and intend for one year cycle.
According to data from the researchspace vehicle "Mars Express", the atmosphere of Mars contains a certain amount of methane. The peculiarity of this gas lies in its rapid decomposition. This means that somewhere on the planet there must be a source of methane replenishment. There can be only two options - either geological activity, traces of which have not yet been found, or the vital activity of microorganisms, which can turn our notion of the presence of foci of life in the solar system.
The characteristic effect of the Martian atmosphereare dust storms that can rage for months. This dense air cover of the planet consists mainly of carbon dioxide with insignificant impregnations of oxygen and water vapor. Such a protracted effect is due to the extremely low gravity of Mars, which allows even a supercharged atmosphere to lift from the surface and hold billions of tons of dust for a long time.</ p>