Rivers of Diamonds in the Universe

AFP, published on Friday, September 02, 2022 at 8:02 p.m.

Some planets could form rivers of diamonds, according to a study published Friday, which used vulgar plastic to recreate the conditions of their supposed appearance in the depths of Uranus and Neptune.

Scientists assumed colossal pressures were turning hydrogen and carbon into diamonds, flowing thousands of miles below the gaseous surface of these icy giants.

The study published in Science Advances suggests that adding oxygen to the mixture would facilitate this formation. The rivers would be of a very particular kind, explained Dominik Kraus, physicist at the German research laboratory HZDR and co-author of the study.

The diamonds would form from a "hot and dense liquid", before flowing gently to the rocky heart of the planets, 10,000 km below the surface, he explained to AFP. They would then spread out there in layers "of hundreds of kilometers or more".

A team of scientists from the HZDR, the German University of Rostock as well as the École polytechnique, tried to recreate these conditions.

She used a simple plastic as a material mixing the necessary ingredients: carbon, hydrogen and oxygen. The same as used in soft drink bottles. She then subjected it to the fire of a powerful laser from the SLAC laboratory in Stanford, in the United States.

“Very, very brief flashes of X-rays of incredible intensity” observed the formation of nano-diamonds, too small to be seen with the naked eye, described Mr. Kraus.

The supply of oxygen, "present in large quantities in these planets", would thus facilitate the formation of diamonds, he explained. The researchers speculate that the diamonds there could be much larger than those produced by Earth's experiment, possibly millions of carats, adds a statement released with the study.

This discovery paves the way for a new way to produce nano-diamonds, which are increasingly useful in many applications, such as medical probes, non-invasive surgery or quantum electronics.

The industrial method of manufacturing nano-diamonds consists of subjecting carbon-rich materials to very strong explosions. "Laser production could offer a cleaner and more easily controllable method of nano-diamonds," said Benjamin Ofori-Okai, a SLAC scientist and co-author of the study.

As for what is really happening in the heart of Neptune and Uranus, the most distant planets of the solar system, we will have to wait for future space missions to find out more. To date, only one NASA probe, Voyager 2, has crossed the two icy planets.