Mercury is the closest planet to the Sun and it is difficult to observe because it is always low on the horizon at dusk evening or morning: a small rocky planet with a diameter less than half that of Earth and a surface similar to that of the Moon, craters.
There are no water or atmosphere during the day and its surface is burned by the intensity of sunlight, while at night the temperature falls below freezing.
Of the five planets visible to the naked eye, Mercury is the most difficult to observe because it always close to the Sun, and generally, you need binoculars to locate the best time to observe it when it is at its greatest angular distance from our star.
Sometimes it can be observed as it passes in front of the solar disk, a phenomenon called Transit.
The temperature of the surface, the equator, when day is at about 450 ° C, during the closest approach to the Sun, however, some areas in the shade, inside craters near the poles, may remain permanently in temperatures below 0 ° C, while the night the surface temperature goes down to -180 ° C.
It looks like the Moon, because the rock surfaces of both bodies are extensively cratered from the impact of meteorites, and the diameter of Mercury is only 40% higher than the moon.
One difference between the two is that Mercury has high mountain ranges up to 3 kilometers that stretch for hundreds of miles, probably formed as a result of contraction and wrinkling of the planet during its cooling phase.
It is believed that inside there is a large iron core extended for three quarters of the diameter of the craters on the Moon as the most recent training is brilliant and surrounded by branched structures of material ejected as a result of meteorite impacts.
Among the main areas of circles are the oldest and uniform inter-crater plains called dotted with small craters.
The structures excavated by debris thrown during the most violent impacts, are closer to the craters on the Moon more than they are on the planet to act as a greater severity.
On its surface there is an extensive lowland, Caloris Basin, reminiscent of the lunar maria, whereas the ninth known volcanic craters.
This planet has always been connected from mythology to the signs of Gemini and Virgo, and has always symbolized "the one who brings the messages of the Gods", portrayed as a guy with boots and helmet with wings that allow it to move at the speed of thought, taking the orders of the gods.
Protecting the thieves, but also those who worked with communication and was invoked to get good news quickly.