Mercury

    Nearest to the Sun is situated the smallest planet Mercury. The distance between them variates between 46 and 70 million kilometers as the planet rotates on a much-flattened elliptical orbit. Flying with the speed of 48 km per second, it makes a full rotation around the Sun for 88 Earth days. That is the duration not only of theMercury year, but also of the Mercury day. The planet is always turned with one of its halves to the Sun. It is only day there and the temperature reaches +420*C. And it is always cold and dark on the other half of the planet where the average temperature is –70*C.     Mercury has a diameter of 4 800 km. Its volume is 19 times smaller than the Earth and it has 18½ times smaller mass. The half turned to the Sun is similar to the Moon and has a lot of mountains and craters. This hypothesis was confirmed by the radiolocations on Mercury, successfully made by Russian scientists in 1962. The planet has an insignificant atmosphere, in which are found traces of carbon dioxide. There are no satellites.