It's raining diamonds across the universe, research suggests

Uranus and Neptune, ice giants where scientists believe diamond rain falls below the surface

It could be raining diamonds on planets throughout the universe, scientists suggested Friday, after using common plastic to recreate the strange precipitation believed to form deep inside Uranus and Neptune.

Scientists had previously theorised that extremely high pressure and temperatures turn hydrogen and carbon into solid diamonds thousands of kilometres below the surface of the ice giants.

Ice giants like Neptune and Uranus are thought to be the most common form of planet outside our Solar System, which means diamond rain could be occurring across the universe.

Under the surface of the planets is believed to be a "hot, dense liquid", where the diamonds form and slowly sink down to the rocky, potentially Earth-size cores more than 10,000 kilometres (6,200 miles) below, he said.

While these diamonds might not be shiny and cut like a "a nice gem on a ring", he said they were formed via similar forces as on Earth.

Kraus said that while the researchers used very clean PET plastic, "in principle the experiment should work with Coca-Cola bottles".

"Very, very short X-ray flashes of incredible brightness" allowed them to watch the process of nanodiamonds -- tiny diamonds too small to see with the naked eye -- as they formed, Kraus said.

- New way to make nanodiamonds? - 

"The way nanodiamonds are currently made is by taking a bunch of carbon or diamond and blowing it up with explosives," said SLAC scientist and study co-author Benjamin Ofori-Okai.

The diamond rain research remains hypothetical because little is known about Uranus and Neptune, the most distant planets in our Solar System.

But a NASA group has outlined a potential new mission to the planets, possibly launching next decade.

He said he is greatly looking forward to more data -- even if it takes a decade or two.

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