Mercury is the hottest planet. He is the closest to the Sun at a distance - 0,387 astronomical units (58 million km).
Due to the fact that mercury is so close to the Sun (angular distance from the Sun does not exceed 28°), it is difficult to observe: in the high latitudes at night it is impossible to see, as it is visible just before sunrise or after sunset.
mercury is named after the Roman God - patron of trade, travelers and thieves, as well as the messenger of the gods. No wonder it got its name in honor of this God that knows no rest: he "runs" across the sky very quickly: a year on mercury, that is, the time required for a full revolution around the Sun, is only 88 earth days. Interestingly, a complete revolution around its axis mercury makes for 58,65 of the day, i.e. the day on mercury is equal to 2/3 of the Mercurian year! That is one Mercurian year mercury manages to turn around its axis at a turn and a half.
Mercury is no change of seasons, as on Earth, because its axis of rotation is at right angles to the plane of the orbit.
Mercury is the smallest planet. Its diameter is only about 5 thousand kilometers. This planet has a negligible force of gravity and a very rarefied helium atmosphere. Particles of helium act to mercury from the Sun, but do not stay long and disappear into space.
Mercury has a metal core whose radius is three quarters (70%or 1800-1900 km) radius of the planet. On the sunlit side temperature reaches +300-420 degrees. On the night side of mercury is cooled to -170 degrees. The surface of this planet is covered with many craters of meteorites.