Sometimes we earthlings can forget just how amazingly absurd our solar system is, and what I'm about to tell you should make you do a double take; on Neptune and Uranus, it rains solid diamonds.
The diamonds form in the oceans of slush that are hydrocarbon-rich. Scientists have speculated that the extreme pressures might split those hydrocarbon molecules into atoms of individual hydrogen and carbon. The carbon will then crystallize into diamonds. These gems were thought to sink like rain through the ocean until they hit the core.
Until now, no one could actually prove that this would work. In a study published on Nature.com
researchers say they were able to duplicate this diamond precipitation using plastic and high-powered lasers.
“Previously, researchers could only assume that the diamonds had formed,” lead author Dominik Kraus, a physicist at the Helmholtz Dresden-Rossendorf research center in Germany, told the magazine Cosmos
. “When I saw the results of this latest experiment, it was one of the best moments of my scientific career.”
Calculations indicate that more than 8000 kilometers below the surface of the giant icy planets Neptune & Uranus the pressure is so intense that the carbon atoms are squeezed to tightly together that they form diamonds which sink to the planet's solid core.
Astronomers speculate that the forces at work deep in the frozen planets of Uranus and Neptune are so powerful that the diamonds that form could weigh in the millions of carats. That's right, MILLIONS of carats. Astronomers also believe that it's possible for both planets to be coated with a thick diamond outer layer.
To duplicate this unearthly intensity, Kraus and his team used an optical laser and one X-ray to produce shock waves that drive through a block of polystyrene - a type of plastic that is a composite of hydrogen and carbon, reminiscent of the oceans on Uranus and Neptune.
“The first smaller, slower wave is overtaken by another stronger second wave,” Kraus explained in a news release. The combination of the two waves over quadrillionths of a second squeezed the polystyrene to 150 gigapascals of pressure - that's more than what exists at the bottom of the earth's mantle - and then heated to over 8,500 degrees. It's at this moment that the diamonds begin to form.
The resulting diamonds were no bigger than a nanometer in length. But Kraus and his team believe that the diamonds that form on Uranus and Neptune are bigger and longer lasting.
“In the planet, you have years, millions of years, and a long range of conditions where this actually can happen,” co-author Dirk Gericke
, of the University of Warwick, told The Guardian
Not only will the results be useful for understanding the out gas giants but for improving the making of lab-grown diamonds. Almost all lab-grown stones are produced via a blasting process, but Kraus and Gericke suggest that using the lasers might make production easier to control and cleaner. These stones are used for drill bits, solar panels, semiconductors and not to mention the instruments that mimic the conditions inside the very gas planets that inspired this research.