Under normal conditions, water exists in three phases: solid (ice), liquid (water), and gas (vapour or steam). This is what textbooks have taught us over the years but beyond the realm of humankind inhabiting Earth — out in the alien world, a different form of water, called plastic ice VII might be present. Several theoretical models in the past have predicted the presence of ‘plastic ice VII’ but for the first time ever, scientists have real proof of its existence.
An international team of researchers at the Institut Laue-Langevin (ILL) in France recently created plastic ice VII by squeezing water up to pressures of 6 gigapascal and heating it to temperatures as high as 327C (620F), using high-calibre instruments, according to the study published in Nature.
The research team used quasi-elastic neutron scattering (QENS), a method that tracks the movement of tiny particles like hydrogen atoms. This confirmed a 17-year-old prediction that hydrogens within Ice VII swivel at a microscopic level when subjected to high temperatures and pressure.
“The ability of QENS to probe both the translational and rotational dynamics is a unique advantage for the exploration of such exotic phase transitions compared to other spectroscopic techniques,” said physicist Maria Rescigno associated with the study.
Also Read | World’s Most Advanced Robot Drops Chilling Job Warning: “How Good Are You?”
Plastic ice VII has properties of both liquid water and solid ice, hence the name. It has a unique interwoven structure when the hydrogen atoms are somewhat disordered.
“The QENS measurements suggested a different molecular rotation mechanism for plastic ice VII than the free rotor behaviour initially expected,” added Ms Rescigno.
However, it remains unclear what happens to this structure when it “melts,” with some theories suggesting the molecules stay in place while the hydrogen atoms move around.
As per the researchers, even the icy planets in our solar system such as Neptune, Uranus or Jupiter’s moon Europa, might have harboured plastic ice VII in the past. The findings could further help the understanding of the geodynamics of icy planets and the differentiation processes of large icy moons.
