Generalities: it is the planet that has, for some aspects, the same features as our planet, even if it is clearly smaller than the Earth, and therefore the development of some forms of life on it isn’t to be excluded, even if elementary. In fact, according to the studies on its conformation, in a remote past, on the surface of Mars liquid water existed.  Problably, within some decades, Mars will be the first planet visited by man.

Features: it is  a rocky planet with a diameter that is about the half of the Earth diameter. Its atmosphere is extremely rarefied and on the ground an atmospheric pressure of about 7 millibars is reached. The Martian atmosphere  is mostly composed by carbonic anidride (95%). Despite the fact that it is a very thin atmosphere it is not calm  at all, as it can produce real wind storms lifting the dust of the ground and whose effects are also observable from the Earth.
Because of the scarce quantity of aqueous vapor, the clouds  formed are few and very thin. They are present on the polar caps and on the top of the great inactive volcanos. On the Martian valleys  early-morning hazes can be created, but the condensation of the little  aqueous vapor present  can’t create any precipitations. The only present water on the Martian ground is trapped as  ice (mixed to solidified carbonic anidride) in the polar caps and probably in the ground, as ice mixed to the ground. The Martian ground is clearly of reddish color, due to the presence of iron oxides. The temperatures on Mars can go down to -130 Celsius degrees on the polar caps, while at midday, in the zones of the equator temperatures of +25 Celsius degrees can be reached.
The satellites of Mars are small (they measure few tens kilometres) and of irregular form. Probably they were asteroids captured by the gravitational strength of the planet.

Observation:  in the terrestrial sky Mars appears visibly as a reddish star. Its brightness is notably variable according to the observation period , its magnitude  is 1.8 in the periods of worse visibility, while it can reach -2.8 in the most favorable periods. Since, unlike the other external planets, Mars  has an evidently elliptical orbit , its distance can vary notably, apart from its angular position in comparison to the Sun. In the case of unfavorable oppositions (as that of 1997), which fall when Mars is found at the aphelion (maximum distance from the Sun), the distance of the red planet from the Earth doesn't go down under  100 million  Km and so its magnitude doesn't go beyond -1.0. The value of maximum brightness  is  reached in reality only every 15 years, during the so-called great " oppositions ", when Mars is taken to around 56 million Km from the Earth.
 

- Visibility of planets during this month

- Mutual posistion of Earth and external planets

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