Mercury
Mercury is one of the four terrestrial planets. Mercury is very similar to the Earth's moon - they both are very old, both have craters, and they have no tectonic plates. Mercury has a very thin atmosphere of atoms that burst off by solar winds. Astronomers have found out Mercury has about 100 billion tons of water and ice! Mercury also has Organic Material. Mercury has shrunk 0.6 to 1.2 miles. Even though Mercury is the closest planet to the sun, Mercury still has ice in its craters. Instead of having an atmosphere, Mercury has a exosphere. Mercury is only one third of Earth's size. Mercury is the second less dense planet after Earth. After Mercury cooled down a billion years after Mercury was born, the crust on the planet crumbled. Mercury has been around for more than 5,000 years. Also Heraclitus believed that both Mercury, and Venus orbited the sun not Earth. Mercury is just like the moon, but way hotter. Mercury gets up to about 800 degrees Fahrenheit because it rotates so slowly and is so close to the sun. It is not advisable to look through a telescope at mercury because it is not safe - it is too close to the sun. The Greeks named Mercury Apollo for its apparition as a morning star, but in the evening they called it Hermes. It usually takes 88 days for Mercury to orbit around the sun and it takes 365 days for Earth and then Pluto it takes 246 years! Also during the night Mercury's temperature would be around -280 degrees Celsius. Only one space craft has ever landed on Mercury (1991).
Citations
http://www.goodteeth.com/facts_mercury.htm
http://nineplanets.org/mercury.html
http://www.windows2universe.org/mercury/mercury.html
http://www.planetsforkids.org/planet-mercury.html
http://nineplanets.org/mercury.html
http://www.windows2universe.org/mercury/mercury.html
http://www.planetsforkids.org/planet-mercury.html