Mercury:

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.