Mercury, the planet nearest to the Sun, has long remained a mysterious body. Because .of the Sun's glare, it is difficult to see it clearly all the mare so because it is very small.
Mercury appears for a brief time as a morning object in the eastern sky, rising just before sunrise. Then it can be briefly seen as an evening object in the western sky, setting just after sunset. Even through the largest telescopes in use today, Mercury appears less distinct than the Moon does to the naked eye. Photographs of the surface of Mercury show craters and wrinkles on it, separated by substantially large smooth areas. Mercury possesses no atmosphere. It has a temperature of almost + 427°C on the side facing the Sun to a low of almost-270°C on its dark side. It has no satefite.