Planet Neptune 3D Screensaver - Version 1.0 Neptune is the eighth planet from the sun, and the outermost gas giant in our solar system. Interestingly enough due to Pluto's eccentric orbit, Neptune is sometimes the furthest planet from the Sun. Orbiting so far from it the planet receives very little heat. Its surface temperature is -218 degrees C. However, the planet seems to have an internal source of heat. Neptune's atmosphere has the highest wind speeds in the solar system, up to 2000 km/h. The planet has large, dark ovals on its surface which astronomers believe are hurricane-like storms. Neptune is never visible with the naked eye so your only chance to have a good look at it is if you download this high-quality Planet Neptune 3D screensaver.