A study discovers that it rains diamonds on two planets
Neptune and Uranus, two ‘ice giants’, have extreme conditions. These types of planets could be the most common throughout the galaxy and beyond.
The great objective of scientists, beyond life on Earth, is to know what is outside our planet: the Moon and the composition of the different planets of our solar system and beyond are firmly on the minds of researchers. Regarding our natural satellite, so far the launch of the Artemis I rocket is not going according to plan, after being postponed twice.
But every dark cloud has a sliver lining, as is often said. Recently, an international team led by the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), the University of Rostock in Germany, and the École Polytechnique in France, has succeeded in demonstrating that on those known as “ice planets”, such as Neptune and Uranus, it “rains” diamonds. Their findings have been published by the journal Science Advances.
To verify this surprising finding, they fired intense laser flashes on a thin film of plain PET plastic. One of the results obtained led the researchers to confirm that diamonds literally “rain” inside these planets, the two furthest from the Sun. This method could also serve to develop a new way of producing nanodiamonds.
Extreme temperatures
The climatic conditions inside these giant icy planets are extreme, reaching several thousand degrees Celsius and with a pressure that is millions of times that of our atmosphere. However, these conditions can be briefly simulated by powerful laser flashes striking a sample of film-like material. On contact, they heat it up to 6,000°C (over 10,800ºF) in just a few seconds and generate a shock wave that compresses the material for a short period of time under extreme levels of pressure.
A change was fundamental to this finding: changing the traditional hydrocarbon film for a PET film, the resin with which normal plastic bottles are made. With hydrocarbon films, "we found that this extreme pressure produced tiny diamonds, known as nanodiamonds," explains Dominik Kraus, a physicist at HZDR and a professor at the University of Rostock. And he adds: “PET has a good balance between carbon, hydrogen and oxygen to simulate the activity of ice planets”.
These experiments were carried out at the SLAC National Accelerator Laboratory in California, which has a powerful accelerator-based X-ray laser, the Linac Coherent Light Source (LCLS). With it they analyzed what happens when the flashes hit this PET film. “The effect of oxygen was to accelerate the splitting of carbon and hydrogen and, therefore, promote the formation of nanodiamonds. It meant that carbon atoms could more easily combine and form diamonds.”
Diamond rain
This discovery only reinforces the assumption that diamonds are raining inside these ice giants. According to Kraus, diamond precipitation is very different from the rain that occurs on Earth. It is believed that under the surface of both planets there is a “hot, dense liquid”, in which diamonds form and sink to rocky cores, more than 10,000 kilometers deep.
And besides, they might not be the only ones. It is likely to occur on many other planets throughout our galaxy and beyond. While ice giants were once considered the exception to the norm, it now seems even clearer that they may be the most common thing outside our solar system.