Water behaves strangely under extreme conditions beyond Earth, according to new research highlighting the unexpected realities that may one day greet future astronauts.
In a recent paper published in Communications Chemistry, a team of scientists from the University of Nevada, Las Vegas, describes their laboratory experiments subjecting water to the harshest conditions found on other planets.
Their laboratory work revealed that water’s atomic structure, appearance, and other properties change under these extreme conditions. With such environments presently still out of reach, the new laboratory work offers a unique window into what may lie beneath the surfaces of distant worlds.
Asymmetrical Water on Other Planets
One of the primary discoveries made in the new research was that, under extreme pressure, water ice can begin to lose its symmetry.
“Water beyond Earth-like conditions has more complex behavior than we ever previously imagined,” said lead author Ashkan Salamat, research lead and director of UNLV’s Nevada Extreme Conditions Lab. “It’s amazing how water can behave under pressure.”
Under normal conditions, compression forces atoms into closer proximity, thereby reducing a material’s volume. In many materials, increasing pressure can also favor more symmetrical atomic arrangements. Yet the UNLV team observed an unexpected departure from this behavior: the atomic structure of water ice became less symmetrical under extreme pressure.
Squeezing Water in the Lab
In an attempt to recreate the intense conditions found deep inside worlds such as Neptune and Uranus, the UNLV team subjected water ice to pressures reaching approximately 35 million pounds per square inch (PSI). For comparison, a typical car tire is inflated to around 30 PSI.
Worlds with such high internal pressures are truly alien environments compared to Earth. No probe has ever entered the deep interiors of Neptune or Uranus to provide firsthand measurements, although Voyager 2 flew past both planets in the 1980s. These ice giants are believed to contain substantial amounts of water, ammonia, and methane deep within their interiors, where extreme pressures and temperatures may produce exotic states of matter.
“We can’t enter the crust or atmospheres of these planets because of distance, but we have data from things like the Voyager program,” said Salamat. “We have an idea of their compositions, and interior pressure and temperatures. And in labs like mine, we can mimic the chemistry and experiment with what could be occurring inside these planets.”
An Unexpected Chemical Shapeshifter
The effects of these simulated planetary conditions were examined using spectroscopy, while two diamonds exerted intense pressure on samples of ice X, an unusual form of water ice that exists under high-pressure conditions. Researchers also used X-ray techniques to investigate the material’s atomic structure.
In replicating these exotic environments, the UNLV team discovered unexpected behavior in water ice. Their findings suggest that, under pressures vastly greater than those encountered at Earth’s surface, the material can undergo structural changes that depart from the symmetrical arrangements previously expected at such extremes.
“Understanding the mechanisms of our solar system and our observable universe is critical for the endeavor of human knowledge,” Salamat concluded. “When we eventually get to these worlds, what are we going to see? We’re really the initial pioneers in trying to answer these questions in the laboratory.”
The paper, “Evidence for Symmetry-Reduction in Solid H2O Above 222 GPa,” appeared in Communications Chemistry on October 20, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.