On Neptune, the weather is typically -353 fahrenheit, compared to earth, at its coldest is -128.6! (in Antarctica) After five minutes on Neptune with out a suit, you would die. If a chemical were to enter your body, you would die because Neptune is made of methane. If you weigh 100 pounds on earth, you will weigh 110 pounds on Neptune. Neptunes surface gravity is about the same as Earths surface gravity because Neptune is made up of gas and it is not as solid as Earth is.