A team of researchers from Germany, the U.S. and the UK managed to confirm the occurrence of diamond rains inside Neptune and Uranus. The proved thesis, according to which the diamonds are shaped from carbon formations affected by pressure and temperatures under the surface of these planets; eventually, these formations settle inside. This is disclosed in the Nature Communications magazine.
"The experiment was performed at the instrument for Matter in Extreme Conditions (MEC), an endstation of the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory", reads the article.
Diamond rains let the researchers explain why the temperature inside Neptune is higher than it's supposed to be. The energy is released from the diamonds falling in the direction of a hard core; it turns into the energy of friction power, which generates heat. However, the final conclusion can only be made when humanity will be able to take a direct look at what's beyond the Neptune's surface.
Neptune and Uranus are the least explored planets in the solar system due to their distance from the Sun, and, respectively, the Earth. So far, no space mission had a task to explore these planets directly.