The three most impressive were all spotted in 1989 by the Voyager 2 space probe, and then named based on their appearances. This differential rotation is the most pronounced of any planet in the Solar System, and results in strong latitudinal wind shear and violent storms. By contrast, the reverse is true for the polar regions where the rotation period is 12 hours. The wide equatorial zone rotates with a period of about 18 hours, which is slower than the 16.1-hour rotation of the planet's magnetic field. The planet is too far from the Sun for this heat to be generated by ultraviolet radiation, which means another heating mechanism is involved – which could be the atmosphere's interaction with ion's in the planet's magnetic field, or gravity waves from the planet's interior that dissipate in the atmosphere.īecause Neptune is not a solid body, its atmosphere undergoes differential rotation. Credit: NASA/ESA/HST/L.Sromovsky/UofWįor reasons that remain obscure, the planet's thermosphere experiences unusually high temperatures of about 750 K (476.85 ☌/890 ☏).

Neptune’s Great Dark Spot, as observed by the Hubble Space Telescope. Because Neptune's atmospheric methane content is similar to that of Uranus, some unknown atmospheric constituent is thought to contribute to Neptune's more intense coloring. Due to its smaller size and higher concentrations of volatiles relative to Jupiter and Saturn, Neptune (much like Uranus) is often referred to as an 'ice giant' – a subclass of a giant planet.Īs with Uranus, the absorption of red light by the atmospheric methane is part of what gives Neptune its blue hue, although Neptune's is darker and more vivid. But with a mass of 1.0243 × 10 26 kg – which is roughly 17 times that of Earth – it is the third most massive, outranking Uranus. With a mean radius of 24,622 ± 19 km, Neptune is the fourth largest planet in the Solar System. Because of this, Neptune's surface is one of the most active and dynamic places in entire the Solar System. That being said, Neptune does have a surface of sorts, (as with the other gas and ice giants) which is defined by astronomers as being the point in the atmosphere where the pressure reaches one bar. As they descended, they would experience increased temperatures and pressures until they finally touched down on the solid core itself.

Neptunes gas