Atmosphere and climate
Monday, 24 February 2014 01:28

The red planet moves on the orbit of an ellipse that substantially affects the seasonal change of the seasons. The distance of Mars from the Sun at aphelion (maximum distance) is equal to 250 million km at perihelion (the minimum distance) is 207 million km.

The period of rotation around the Sun is 687 days, the period of rotation around its axis in 24 hours 37 minutes 22.6 seconds. The average day is 24 hours 39 minutes 35 seconds (the Martian day – Sol). The angle of inclination of the axis of rotation is equal to 25.2° to the plane of the orbit. The changing seasons on Mars occur as on Earth. However, the duration of twice that much. Due to the elliptical orbit of the planet and larger orbital eccentricity for the two hemispheres make different times of the year. In other words, when in the southern hemisphere summer to Northern winter and Vice versa. When Mars passes the perihelion in Northern hemisphere is winter and in southern - summer. With the passage of the aphelion in Northern summer, Southern winter. On Mars in summer (winter) is 160 days, fall is 199 days, in winter (summer) – 182 days, spring 146 days. When the change of seasons comes on planet, we can see melting polar caps, displacement of gas between the hemispheres and the wind speed can reach 100 m/s, causing dust storms.

Atmospheric pressure is low, its average assumed value is 6.36 millibars. This value is of the earth at a height of 40 km, the Atmosphere consists of the following main substances: carbon dioxide (CO2) – 95.32%, nitrogen (N2) – 2.7%, argon (Ar) – 1.6%, oxygen 0.13% (O2), carbon monoxide – 0.08% (CO), water vapor – 0.021% (H2O), oxides of nitrogen – 0.01% (NO). Spectrographic study of Mars in 2009, proved the existence in certain areas of the planet methane gas (CH4). On Earth 90% of methane is produced by bacteria in plants and animals. In the thin Martian atmosphere under influence of solar radiation methane decays within a few months (in the earth atmosphere the methane decomposes over 300 years), it testifies about the existence of the source of methane on the red planet. The source may be volcanic processes - the contact of volcanic rock (basalt) and water. Also methane can produce underground bacteria.