The planet of our solar system that is the farthest from the Sun is Neptune (2.8 billion miles of distance from the Sun), but there are still dwarf planets further out, notably Pluto that was demoted to dwarf planet in 2006. The Neptune atmosphere is composed mostly by hydrogen, and smaller amounts of helium and methane, making a blue coloration of the planet (methane absorption of red light cause this effect), the planet has -373 F° as the average temperature, therefore Neptune has a thick, windy atmosphere.