Neptune is the eighth and outermost planet in our solar system.
It is the fourth-largest planet by diameter and the third-largest by mass;
Neptune is 17 times the mass of Earth and is slightly more massive than its near twin Uranus which is 14 Earth Masses, but slightly smaller due to its higher density.
Neptune's atmosphere is primarily composed of hydrogen and helium, with traces of methane that account for the planet's blue appearance.
Neptune's blue colour is much more vivid than that of Uranus, which has a similar amount of methane, so an unknown component is presumed to cause Neptune's intense color.
Neptune also has the strongest winds of any planet in the solar system, with estimates as high as 2,500 km/h or 1,500 mph.