Mars is the fourth planet of the Solar System. Form leaves from denominated telluric planets (of rocky nature, as the Earth) and is first of outer planets to the Earth orbit. He is, possibly, most similar to the Earth.

        Tycho Brahe measured with high accuracy the Mars movement in the sky. The data on the retirement pretend (bows) allowed Kepler to find the elliptical nature of their orbit and to determine the laws del planetary movement known like laws Kepler.

            The superior or outer planets, never happen between the Sun and the Earth neither never is seen them in flood nor in quarter; their phases are little noticeable, fact that is easy to demonstrate geometrically. Considering the Sun-Earth-Mars triangle, the phase angle is the one that forms the seen Sun and the Earth from Mars. It reaches his maximum value in the quadratures when triangle STM is Earth rectangle. For Mars, this angle of phase is never greater of 42, and its hunchbacked disc aspect is analogous to which it presents/displays the Moon 3.5 days before or after the Full Moon. This phase, visible with a fan telescope, did not manage to be Vista by Galileo, that only supposed its existence.

            Mars was the Roman God of the war and his equivalent Greek was called You plow. The red color of the Mars planet, related to the blood, favored that it was considered him from old like a symbol of the God of the war. Sometimes reference to Mars like the Red Planet is made.

            Of the duration of the sidereal day it is deduced easily that the solar day h 39 lasts in Mars of 24 min 35.3 s. The solar day half or time between two consecutive steps of the average Sun by the meridian of the place, 41 lasts 24 h min 18.6 s. a Martian day bond, therefore, 1.029 days terrestrial. The solar day in Mars has, like in the Earth a variable duration, which must that the planets follow elliptical orbits around the Sun that are not crossed with uniformity. Despite in Mars the variation he is greater by his high eccentricity. For greater comfort in their works, the people in charge of the North American missions of exploration of Mars by automatic soundings have decided unilaterally to give to the Martian day the sun name , without worrying about the fact that that word means French ground and designates in Castilian the solar light or, written with capital letter, the central star of our planetary system.



Fourth planet of the Solar System


            The Martian year lasts 687 days terrestrial or 668.6 suns. A Martian calendar could consist of two years of 668 days by every three years of 669 days.

            The Mars poles are indicated by two polar caps of overwhelming color white, which they have facilitated much the determination of the angle that forms the equator of the planet with the plane of its orbit, angle equivalent for Mars to the camber of the Earth ecliptic. The measures done by Camichel on cliches obtained in the French observatory of the Pic du Midi, have given for this angle 24 48'. From the space reconnaissance a value of 25,19 is accepted, a little greater than the camber of the ecliptic (23 27 '), reason by which, Mars it has seasonal periods similar to those of the Earth, although their stations are longer, since a Martian year is almost twice more length than a terrestrial year

         Mars I located it during the month of March of 1982 when it was 14 years old from the Majorcan locality of Inca (Majorca, Spain). It had been four years of which I began to be become fond of to Astronomy and therefore, was for my whole a landmark discovering it, for that reason personally it is still pleasing observing to me it when it is in opposition with that reddish color unmistakable.   


Orbital characteristics
Average Dist. of the Sun 1.524 UA
Average radio 227.900.000 km
Eccentricity 0,055
Orbital period (sidereal) 1.88 years
Period of rotation 24h.37m.
Orbital speed average 24,13 km/s
Inclination of the axis 23,98
Number of satellites 2


Physical characteristics
Equatorial diameter 6,796 km
Mass 0,151Tierra
Average density 3,94 g/cm
Superficial gravity 0.38 Earth
Speed of escape 5,0 km/s
Average Temp. superf.: Day 17 C
Average Temp. superf.: Night -143 C
Atmosphere CO2



                    In the page Web you can obtain more data of each one of our planets and the dwarf planets defined by the IAU of our Solar System.


Masm Last update 2006-08-28)