Scientists have succeeded in creating a type of ice that forms at temperatures that are almost as hot as the Sun, and pressures millions of times greater than Earth's atmosphere.
Known as superionic ice, it is believed to form at these extreme temperatures and pressures and melts at an astonishing 4,700°C (8,500°F). For comparison, the surface of the Sun is about 5,500°C (9,940°F). A study describing the findings was published in Nature Physics back in February.
As Live Science notes, making the ice “was complicated”. The team first compressed water into an ultrastrong cubic crystalline ice, with diamond anvil cells applying a pressure 25,000 times Earth’s atmospheric pressure. They then used laser beams to heat and compress the cells even more, reaching pressures of 2 million (yes, million) Earth atmospheres.
Superionic ice forms when “oxygen atoms are locked into a crystal structure, but the hydrogen ions move around, making the ice simultaneously solid and liquid, somewhat similar to lava,” noted Seeker. It’s essentially composed of a fluid of hydrogen ions that run through a lattice of oxygen, and it's thought this unique form of ice could be found naturally inside the ice giants Uranus and Neptune.
“It’s… mind-boggling that frozen water ice is present at thousands of degrees inside these planets, but that’s what the experiments show,” Raymond Jeanloz from the University of California, Berkeley, a co-author on the study, said in a statement. The Lawrence Livermore National Laboratory (LLNL) in California and the University of Rochester in New York were also involved in the research.
Superionic refers to a phase of water where it behaves as both a solid and a liquid. Although it has been indirectly seen before, this study was the first to ever find experimental evidence for it. It was first predicted to exist back in 1988.
The findings suggest that Uranus and Neptune, instead of being relatively “fluffy planets”, might actually contain a large mantle of superionic ice, which could explain their unusual magnetic fields. They are extremely tilted to the planet’s axis, 59 and 47 degrees respectively, compared to 11 degrees on Earth.
“This is particularly relevant as NASA is considering launching a probe to Uranus and/or Neptune, in the footsteps of the successful Cassini and Juno missions to Saturn and Jupiter,” the statement noted.
The team hope to apply their methods to higher levels of compression, to try to work out what the interiors of other planets like Saturn and Jupiter look like, which contain a lot of compressed helium.