Higher Technical School scientists in Zurich (Switzerland) denied the theory explaining the origin of the unusual magnetic fields of Neptune and Uranus. The mechanism of their occurrence remains an unresolved mystery of astrophysics. This is reported in the article published in the journal Proceedings of the National Academy of Sciences.
It is known that the magnetic fields of uranium and neptune are strongly rejected from the axis of rotation and are shifted away from the center of both planets. This may be explained by the unusual internal structure of the planets, for example, convection in a layer consisting of an electrically conductive liquid. This layer, in turn, must surround a stable layer in which there is no circulation due to high viscosity.
Computer simulation shows that water and ammonia, the main components of the atmosphere of uranium and neptune, at very high pressures and temperatures are in superionic state, possessing the properties of a solid and liquid. Oxygen and nitrogen form a lattice, and hydrogen ions in it remain movable. Superinic water can be at the depth of a stable layer, but it is still not known whether the substance is indeed in such a state can suppress convection.
Scientists conducted experiments with ammonia at high pressure and high temperature to determine the elasticity of the superion state. This characteristic is able to affect the thermal convection in the mantle of the planet. In the course of study, ammonia was placed in a container with a diameter of 100 micrometers, which is then clamped between two diamond tips, which allows to damage the samples extremely high pressure. The elasticity of ammonia, heated then up to two thousand degrees Celsius, is measured using an infrared and green laser.
It turned out that the superona ammonia, although demonstrated elasticity sufficient to form a stable layer, has too low viscosity to suppress convection. Thus, the existence of distorted magnetic fields in uranium and Neptune remains a mystery.