The planet closest to the Sun got its name back in the ancient period. Mercury was a Roman god, the patron of travelers and trade. And also a fast-moving messenger of the gods. It is for the rapid movement of the celestial vault that the planet nearest to the Sun - and it is the fastest body in our sky - received its name.
Basic statements
This planet is closer to the Sun than the Earth is almost three times. Mercury's proximity to its star causes its highly elongated orbit and rapid rotation around it - in just 88 days. And this is faster than the rotation of the Earth in half. It is interesting that the revolution around its own axis is made by the planet in about 59 terrestrial days. It is too Is due to the approach to the star and the force of its gravity, because the diameter of the planet is more than three times smaller than the earth's, not to mention the mass. It follows that the Mercurian day lasts two-thirds of the year here. Mercury for a long time was the smallest planet of the terrestrial group, and after Pluto's deprivation of the planet's status - which happened a few years ago due to the revision of scientists of this very concept - and at all became the smallest planet in the solar system. Interestingly, he is even smaller than the satellites of Jupiter and Saturn - respectively, Titan and Ganymede. Though the latter can not be called planets. For a long time, almost nothing was known about Mercury. His full study was begun only during the space race of the Cold War. In 1973, in the direction of this body was launched the Mariner 10, which received the first good shots of the planet (incidentally, "looking" closer to Venus).
Weather on the planet
Mercury does not actually have any atmosphere, but there are a small number of gases we know: hydrogen, sodium, oxygen, argon, potassium and some others. Despite the fact that on most of its surface the planet closest to the Sun is a real hell (the temperature here often reaches 400 degrees Celsius), there are also zones where sun rays never reach. Not so long ago, in some deep craters of the Moon, real water ice was discovered. Astrophysicists suggest that Mercury, most likely, also contains ice in the craters located at its poles. The images that were obtained thanks to the Mariner-10 demonstrated that the planet closest to the Sun is very similar in structure to the Moon: it is even more cratered. The entire surface is covered with a long-fragmented dark substance such as basalt. The composition of the body itself is mostly iron - about 70%. Most likely, the core of it also consists. However, in all likelihood, the planet closest to the Sun has long cooled inside and has no geological activity.
Further research
Today, a joint program of European and Japanese experts is developing a program in which within the next few years, two spacecraft will be sent to Mercury, one of which will descend to the planet and explore its surface and depths, and the other will study its magnetic field.