Just because Mercury is the closest planet to the Sun does not mean it is the hottest. In fact Venus is. Gravity on Mercury is less than the gravity on Earth since it is a smaller planet. Mercury is named after the roman god messenger because Mercury seemed to them to be the fastest planet and the roman god messenger was fast. The sun appears 2 and a half times larger in Mercury's sky compared to the Earth's.If you weigh 100 pounds on Earth, you would only weigh 37 pounds on Mercury. Mercury has virtually no atmosphere. It however has small traces of an atmosphere which consists minute quantities of Hydrogen, Oxygen, Sodium, Potassium and argon. Mercury has no rings.