Inside the giant icy planets it can rain diamonds

The universe is stranger than you can imagine, and in the depths of space, there are wild and exotic exoplanets to be found – planets with Glowing rivers of lavaOr planets under gravitational forces that strong shaped like a soccer ball. We can add to this list another class of alien planets, those on which it rains diamonds.

The effect of diamond rain is believed to occur in the depths of ice giants such as Uranus and Neptune, and it was Recreated in a lab here on Earth In 2017. Now, researchers have found that this effect is not just a rare coincidence but may be more common than previously thought.

Diamond rain can occur in the depths of icy giant planets and is more common in the presence of oxygen. Greg Stewart / SLAC National Accelerator Laboratory

An international group of researchers working with the SLAC National Accelerator Laboratory has created the diamond rain effect by placing hydrogen and carbon under extremely high pressures. But in this new research, they wanted to make conditions more realistic for what the interior of an icy giant planet would be like by including other elements present, such as oxygen.

To simulate this mixture of chemicals, the researchers used a familiar material — polyethylene terephthalate plastic, like that used in good packaging, which turned out to be chemically similar to the conditions they wanted to make. “PET has a good balance of carbon, hydrogen and oxygen to simulate activity in icy planets,” explained one of the researchers, Dominic Krause, from the University of Rostock.

The researchers used a high-powered laser to create shock waves in the plastic, and then observed how X-rays bounced off it. This allowed them to see how the tiny diamond was shaped. The diamonds produced in the experiment were very small, called nanodiamonds, but about 5,000 miles below the surface of a giant ice mass much larger diamonds could form, as they would fall toward the planet’s ice core. Diamonds can sink even into the core and form a thick layer of diamond.

In the new experiments, the team found that when oxygen was included, nanodiamonds grew at lower temperatures and pressures, meaning that the presence of oxygen makes diamond rain formation more likely. “The effect of the oxygen was to speed up the splitting of carbon and hydrogen and thus encourage the formation of nanodiamonds,” Krause said. “This means that the carbon atoms can combine more easily and form diamonds.”

With this discovery, the researchers now want to try the experiments again and include chemicals like ethanol, water and ammonia to more closely model the environments of the ice giants.

“The fact that we can recreate these extreme conditions to see how these processes operate at very fast and very small scales is exciting,” said SLAC scientist and collaborator Nicholas Hartley. “Adding oxygen brings us closer than ever to seeing the full picture of these planetary processes, but there is still more work to be done. It is a step on the way towards getting the most realistic mixture and seeing how these materials really behave on other planets.”

Publish the research in the journal science progress.

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