The Inner Planets

Mercury:	A day on Mercury is 59 Earth days, but a Mercury year is only 88 Earth days. Mercury has no atmosphere and resembles the moon. It also has extreme surface temperatures ranging from —170° C to 430° C.
Venus:	Venus rotates on its axis counter-clockwise, while most planets and moons rotate clockwise. Venus has an atmosphere, but it is composed of carbon dioxide, sulfuric acid, hydrochloric acid, and hydrofluoric acid. The thick atmosphere holds in heat so the surface temperature is around 480° C—hot enough to melt lead! The atmospheric pressure on Venus is 90 times greater than Earth’s. Neither Mercury nor Venus has any moons.
Mars:	Mars has polar ice caps. The north cap is covered by frozen water, but the south cap by carbon dioxide ice. Mars has many impact craters and has evidence of volcanoes. Mars has two tiny moons which resemble potatoes.