Mercury


 * Mercury

Mercury is the closest planet to sun and also the smallest planet in our solar system. Mercury is a terrestrial planet, meaning that it is rocky and solid. Due to its small orbit, this planet orbits the sun in 88 days.

The planet has similar characterises to earth’s moon. They are both heavily crated, they don’t have any natural satellites and they don’t have an atmosphere.

The planet consists of an iron core which generates a magnetic field, 1% as strong as earths and is very dense due to the sheer size of the core. The mass of Mercury is quite small so the force of gravity generated on Mercury is about one-third of Earth’s.

The temperatures on Mercury vary, depending on the different location. Temperature ranges from −180 °C to 430 °C with the subsolar point being the hottest (the point where the sun is directly overhead to the planet) and the coldest being at the bottom craters near the poles.

Because Mercury is a very small planet, it isn’t able to generate enough gravity to have a permanent and stable atmosphere. Although there isn’t a strong gravity field, Mercury does have a tenuous atmosphere containing hydrogen, helium, oxygen, sodium, calcium and potassium .**

http://en.wikipedia.org/wiki/Mercury_%28planet%29 http://www.nineplanets.org/mercury.html http://www.aerospaceguide.net/planet/planetmercury.html