Mercury

This is the closet planet to the Sun. It is small, only a little bigger than Earth's moon. Mercury has high mountains and flat land. It also has lots of craters which look like holes in the ground. These were probably caused by asteroids and meteorites that crashed into it.

Mercury rotates on its axis once every 58 days, 15 hours and 36 minutes. It takes about 88 Earth days to go around the Sun. Mercury is named after the Roman messenger god whom people believed could moved through the sky on winged feet.

The side of Mercury that faces the Sun is hotter than fire  because it is so near the Sun. But the planet has no air around to hold the heat in. So the side that away from the Sun is freezing cold.

Mercury has low gravity so you would weigh about three times lighter than you do on Earth. You could not breath on Mercury without oxygen tanks. The core (central part) of Mercury is iron.