A strange type of ice except at very high temperatures

Arabia Weather - Strange things happen inside planets, where familiar materials are exposed to intense pressure and heat. It is possible that vibrational movements of iron atoms will occur within the solid inner core of the Earth, and it is also possible for the formation of heavy, hot black ice, which is both solid and liquid at the same time, inside Uranus and Neptune, the two giant gas planets rich in water.

Five years ago, scientists recreated this strange ice, called superionic ice, for the first time in laboratory experiments; Four years ago, they confirmed its existence and crystal structure. Then just last year, researchers at several US universities and the Stanford Linear Accelerator Center Laboratory in California (SLAC) discovered a new phase of super-ionized ice.

Their discovery deepens our understanding of why Uranus and Neptune have irregular magnetic fields with multiple poles.

From our terrestrial surroundings, you would be forgiven for thinking that water is a simple molecule consisting of a single oxygen atom bonded to two hydrogen atoms that settle into a fixed position when the water freezes. But highly ionized ice is strangely different, yet it may be among the most abundant forms of water in the universe, supposedly filling not only the interiors of Uranus and Neptune, but also similar exoplanets.

A strange type of ice except at very high temperatures

These planets have extreme pressures two million times Earth's atmospheric pressure, and their interiors are as hot as the surface of the Sun, which is where water becomes alien.

In 2019, scientists confirmed the predictions of physicists who worked in 1988, discovering that highly ionized ice consists of a skeletal structure containing a rigid cubic lattice that traps oxygen atoms, while ionized hydrogen atoms are released and flow through that lattice in a manner similar to the flow of electrons through metals. . This highly ionized structure gives the ice its electrically conductive properties and keeps its melting point low, maintaining a frozen state even at extreme temperatures.

This gives highly ionized ice its conductive properties. It also raises its melting point so that frozen water remains solid at extreme temperatures. In this latest study, physicist Ariana Gleason of Stanford University and her colleagues bombarded thin strips of water, sandwiched between two layers of diamond, with some ridiculously powerful lasers.

Successive shock waves raised pressures to 200 gigapascals (2 million atmospheres) and temperatures of about 5,000 K (8,500 degrees Fahrenheit) — hotter than the temperatures of the 2019 experiments, but at lower pressures.

Researcher Gleason and her team explained in their paper, which they published in January 2022: “Understanding water-rich exoplanets similar to Neptune requires careful analysis of the state of water under conditions of pressure and temperature associated with the internal composition of each planet.”

X-ray diffraction then revealed the crystalline structure of the hot, dense ice, where pressure and temperature conditions were maintained for a short period of about a fraction of a second.

The resulting diffraction patterns also confirmed that the ice crystals were in fact a new phase distinct from the superionized ice observed in 2019. The newly discovered superionized ice, Ice XIX, has a body-centered cubic structure and increased conductivity compared to its predecessor from 2019, Ice XVIII. . .

Electrical conductivity is important here because moving charged particles generate magnetic fields. This is the basis of dynamo theory, which describes how conductive fluids, such as the Earth's mantle or the interior of another celestial body, give rise to magnetic fields. If more of the interior of a Neptune-like ice giant were sucked in by a soft solid, and less by a rotating liquid, that would change the type of magnetic field produced. If the planet has two superionic layers with different conductivities, as Gleason and his colleagues suggest, the magnetic field generated by the outer liquid layer would interact with each of them differently, making things even stranger.

Here, Gleeson and his colleagues conclude that the enhanced electrical conductivity of a layer of superionized ice similar to Ice

If so, it would be a satisfying result more than 30 years after NASA's Voyager 2 space probe, launched in 1977, flew by the two ice giants in our solar system and measured their unusual magnetic fields.

Source: sciencealert