The planet that is farthest away from the sun is Neptune. The planet Neptune is located approximately 2.8 billion miles away from the sun, making it the eighth planet in our solar system. This planet is referred to as an "ice giant", which means that it is primarily composed of "icy" materials, such as water, methane, and ammonia, instead of just being composed of gas. Pluto was previously regarded as the ninth and most distant planet, but it was later classified by the International Astronomical Union as a dwarf planet in 2006. Interestingly, there are 20-year intervals between Pluto’s 248-year orbit around the sun, where it is actually closer to the sun than Neptune, with the last such period being between 1979 and 1999.