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‘Weird, hot, black ice’: Scientists discover new phase of water

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November 21, 2021 at 9:00 a.m. EST
An artist’s rendering of a laser compression experiment: High-powered lasers focus on the surface of a diamond, generating a sequence of shock waves that propagate throughout the sample assembly, simultaneously compressing and heating the initially liquid water sample, forcing it to freeze into the superionic water ice phase. (Millot, Coppari, Hamel, Krauss/LLNL)

What happens when you crush water between two diamonds and heat it up with a laser?

If you didn’t think of the answer — “It forms weird, hot, black ice” — don’t worry. In recent years, researchers have discovered so many funky forms of ice — over 18 in all — that it’s hard to keep track. Now, they’ve hit on a new phase of water that could explain how icy planets form.

It’s called superionic ice, and until recently it had only been glimpsed for a fleeting moment. In a study published in the journal Nature Physics, researchers managed to create the substance using the same high temperatures and pressures that can be found inside ice giants Uranus and Neptune.

Water is even weirder than we knew, supercool study shows

Ordinary ice is made of crystals formed by the hydrogen and oxygen atoms that make up water. Hydrogen atoms connect oxygen atoms into a solid, latticelike structure.

In superionic ice, the hydrogen atoms float around inside an oxygen lattice instead. This leads to ice that can conduct electricity. The ice is less dense than ordinary ice, and is black in color.

It’s tough to create this odd ice, and earlier, researchers had managed to observe it for just a few billionths of a second. In the new experiment, they managed to observe it for a millionth of a second before it disintegrated. In the experiment, the researchers heated the water to over 11,000 degrees Fahrenheit. Since they did so under the same types of high pressure that exist inside dense planets, the study produced superionic ice instead of a puff of steam.

Scientists say that a lot of the universe’s water exists in this hot, superionic form, and they’re trying to understand its properties, which include the ability to generate the magnetic fields that protect people and organisms from the sun’s blistering radiation. Since magnetic fields allow planets to sustain life, the hunt for superionic ice could point to other places where life is possible.

The new phase of water joins a long list of recently discovered types of ice. But since the experiments are so fleeting, learning more is a challenge.

“It’s a new state of matter, so it basically acts as a new material,” said Vitali Prakapenka, a University of Chicago research professor and scientist at the Energy Department’s Argonne National Laboratory who co-wrote the study, in a news release. “And it may be different from what we thought.”

Earth is now losing 1.2 trillion tons of ice each year. And it’s going to get worse.

A supercool science story about a really cold thing

Dear Science: What are these strangely beautiful ice formations?