Mercury is the first planet of our Solar System and next to the Sun, it is to only 0.387 astronomical units (UA) but has an eccentric orbit of 0,20. Form leaves from rocky inner planets and its diameter is of only 4,879 km.  To the being so small and next to the Sun it is difficult to locate it from the Earth.

            Mercury I located the 7 to it of June of 1987 when it was 19 years old from the Majorcan locality of Cán Picafort (Majorca, Spain). One was in the constellation of Gemini and observing from the North hemisphere it was easy to locate it because the inclination of the ecliptic in Gemini is almost vertical with respect to the horizon and it was possible to be observed in the first times of the night.



First planet of our Solar System.

            It really is difficult to locate to Mercury because never one moves away more of 23º with respect to the Sun, since one is an inner planet, that is to say, is between the Sun and the Earth. It has a rotation of 58.7 days that peculiarly corresponds to 2/3 of its period of transfering around the Sun. These synchronizations we found in several examples in planets and satellites of our Solar System.

            Mythologily represented the God of the messengers, you can have more information of its mythology in the Web.

            Mercury is a planet that has a very tenuous atmosphere and therefore, with the last images of the space probes that have happened through the planet have observed a surface similar to the spot by the immense amount of craters that there are in his surface.


Orbital characteristics
Average Dist. of the Sun 0.387 UA
Average radio 57.910.000 km
Eccentricity 0,20563069
Orbital period (sidereal) 87d 23,3h
Orbital period (sinódico) 115.88 days
Orbital speed average 47,8725 km/s
Inclination 7,004°
Number of satellites 0


Physical characteristics
Equatorial diameter 4,879.4 km
Superficial area 7,5 × 107 km²
Mass 3,302×1023 kg
Average density 5,43 g/cm³
Superficial gravity 2,78 m/s²
Period of rotation 58d 15,5088h
Axial inclination
Albedo 0,10-0,12
Speed of escape 4,25 km/s
Average Temp. superf.: Day 623 K
Average Temp. superf.: Night 103 K
Skin temperature
mín. average máx.
90 K 440 K 700 K


Atmospheric characteristics
Atmospheric pressure outlines
Potassium 31,7%
Sodium 24,9%
Atomic oxygen 9,5%
Argon 7,0%
Helium 5,9%
Molecular oxygen 5,6%
Nitrogen 5,2%
Carbon dioxide 3,6%
Water 3,4%
Hydrogen 3,2%



                    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)