Mercury

Mercury is the smallest rocky planet of the Solar System, and of all the planets it orbits the closest to the Sun. In the sky we can see it as a bright spot even without a telescope.



At first glance Mercury resembles the Moon, but without the dark "seas". Its surface is covered with a large number of craters (from small recesses to giant impact basins about the size of a quarter of the planet), and there are deep cracks in the crust too. Roughly one billion years ago the Mercury's surface was being formed by volcanic activity that gradually subsided and now Mercury is geologically a dead body.



The planet rotates around its axis of rotation once in every 59 days. In combination with the movement around the Sun, the solar "day" here lasts about 176 of terrestrial days.



Mercury has no atmosphere that would protect it through the day from solar heat and from cooling at night. Thanks to this the day surface temperature reaches to 430 °C, while the night temperature drops to -170 °C.