Our Planet Neptune Sticker features the eighth and farthest planet from the Sun in our solar system. It is a gas giant composed mainly of hydrogen, helium, and methane, which gives its distinctive blue color. Neptune is the fourth largest planet by diameter but the third most massive planet. Neptune has a complex ring system and is orbited by 14 known moons, the largest of which is Triton. By the way, Neptune has a magnetic field that is about 27 times more powerful than Earth's magnetic field.