Mercury
Mercury is the closest planet to the sun, it is hot, dry, barren and dusty. It is the second smallest planet in our solar system. Since it is the closest to the sun, it is difficult to see with the naked eye. It is seen as a twinkling light near the horizon as a morning or evening star. It is usually seen in the Northern Hemisphere in May or October. Night temperatures can dip below 0 degrees Fahrenheit to as low as –315 degrees Fahrenheit.
During the day, the high could reach around 650 degrees Fahrenheit. The United States launched Mariner 10 in 1974. It reached Mercury and took most of the pictures we have today. Many scientists believe gigantic comets and asteroids crashing on the surface cause the craters on Mercury’s surface.
One very surprising discovery from Mariner 10 was that they discovered that Mercury has an atmosphere, a very small one at that. It was surprising because an atmosphere was not suspected with such low gravity. Another surprising discovery was that Mercury has a magnetic field. The strength of this field is only 1 per cent of our Earth. It has two magnetic poles. The dangerous temperatures on Mercury have prevented samples of soil from being collected. Pierre Gassendi in Milan, Italy first observed Mercury.