Neptune
Neptune is the eighth planet of our Solar System. Its orbit around the Sun is in 165 years, while it’s rotating around himself in 16 hours.
The core of Neptune is a solid core of iron, nickel and sulfur. It is surrounded by a mantle of water and ammonia and above it there is the atmosphere consisting mainly of methane, hydrogen and helium. As with Uranus, the absorption of red light by atmospheric methane is part of what gives Neptune its blue color, though Neptune’s intense light blue shades differ from the lighter bluish-green of Uranus. Since the atmospheric content of Neptune’s methane is similar to that of Uranus, some unknown atmospheric component is thought to contribute to Neptune’s color. Its upper atmosphere has a temperature of -200 °C and has very strong storms. Τhe most powerful winds in the solar system blowing at 2100 km / h have been recorded in Neptune. Atmospheric models show that the troposphere is divided into clouds of different compositions depending on altitude. As in Uranus, there is a possibility of a “diamond rain” (https://www.americanscientist.org/article/on-neptune-its-raining-diamonds).
The magnetic field of Neptune is bipolar with the dipole axis tilted with the axis of rotation but the centre of the dipole is not the same as the center of the planet. The magnitude of the magnetic field is about 1/5 of the magnitude of the Earth’s magnetic field.
Like the other giants, it has satellites and faint rings. Its largest and only spherical satellite is Triton, among the 14 known satellites. Six rings, analogous to Uranus and Saturn, have been observed, which are quite thin and dim. They consist mainly of frozen methane and dust particles.
Voyager 2 (1989) approached the planets and observed a large dark spot, comparable to Jupiter’s Red Spot. Since then, no other spaceship has visited the planet.