February 26, 2024

A “Fundamental Discovery” in Science – New Form of Salty Ice Could Exist on Extraterrestrial Moons

This satellite image shows red streaks throughout the surface of Europa, the smallest of Jupiters four large moons. The discovery of brand-new kinds of salty ice might describe the material in these streaks and offer ideas on the composition of Europas ice-covered ocean. Credit: NASA/JPL/Galileo
The red streaks crisscrossing the surface of Europa, among Jupiters moons, stand out. Researchers believe it is a frozen mixture of water and salts, but its chemical signature is mysterious since it matches no known compound in the world.
A research group led by the University of Washington may have fixed the puzzle with the discovery of a brand-new type of solid crystal that forms when water and table salt integrate in high-pressure and cold conditions. Scientists think the brand-new compound created in a laboratory in the world might form at the surface area and bottom of these worlds deep oceans.
Released on February 20 in the Proceedings of the National Academy of Sciences, the research study reveals a new combination for 2 of Earths most common compounds: water and sodium chloride, or salt.

This satellite image shows white streaks throughout the surface of Ganymede, the biggest of Jupiters moons. The discovery of brand-new kinds of salty ice might explain the product in these streaks and offer ideas on the composition of Ganymedes ice-covered ocean. Credit: NASA/JPL/JUNO
” Its rare nowadays to have essential discoveries in science,” said lead author Baptiste Journaux, a UW acting assistant teacher of Earth and area sciences. “Salt and water are really well known at Earth conditions. We have to renovate all the essential mineralogical science that people did in the 1800s, however at high pressure and low temperature level.
At cold temperatures water and salts integrate to form a rigid salted icy lattice, referred to as a hydrate, held in place by hydrogen bonds. The only formerly understood hydrate for salt chloride was an easy structure with one salt particle for each two water molecules.
However the two new hydrates, found at moderate pressures and low temperatures, are strikingly various. One has two sodium chlorides for every 17 water molecules; the other has one sodium chloride for every single 13 water particles. This would discuss why the signatures from the surface area of Jupiters moons are more “watery” than expected.
” It has the structure that planetary scientists have actually been awaiting,” Journaux said.
Researchers discovered two new crystals made from water and table salt at low temperature levels, below about minus 50 C. The recognized structure (left) has one salt particle (yellow and green balls) to 2 water molecules (red and pink balls). X-ray imaging let researchers figure out the position of specific atoms in the brand-new structures. The center structure has two salt chloride molecules for every 17 water molecules and remains stable even if pressure drops to near vacuum, as would exist on a lunar surface area. The structure on the right has one salt chloride molecule for each 13 water particles, and is steady just at high pressure. Credit: Baptiste Journaux/University of Washington
The discovery of brand-new types of salty ice has value not simply for planetary science, but for physical chemistry and even energy research study, which utilizes hydrates for energy storage, Journaux said.
The experiment included compressing a tiny bit of salted water in between 2 diamonds about the size of a grain of sand, squeezing the liquid up to 25,000 times the standard atmospheric pressure. The transparent diamonds enabled the team to see the process through a microscope.
” We were trying to determine how including salt would alter the quantity of ice we could get, because salt serves as an antifreeze,” Baptiste said. “Surprisingly, when we put the pressure on, what we saw is that these crystals that we were not expecting started growing. It was a really serendipitous discovery.”
Such cold, high-pressure conditions developed in the laboratory would be common on Jupiters moons, where researchers think 5 to 10 kilometers of ice would cover oceans as much as a number of hundred kilometers thick, with even denser kinds of ice possible at the bottom.
” Pressure just gets the molecules more detailed together, so their interaction modifications– that is the main engine for variety in the crystal structures we discovered,” Journaux stated.
As soon as the recently found hydrates had actually formed, among the two structures stayed stable even after the pressure was released.
” We identified that it stays stable at standard pressure as much as about minus 50 C. If you have an extremely briny lake, for example in Antarctica, that might be exposed to these temperature levels, this freshly found hydrate might be present there,” Journaux said.
This image reveals the recently found hydrate that has two sodium chloride molecules for each 17 water particles. This crystal formed at high pressure but remains steady at cold, low-pressure conditions. Credit: Journaux et al./ PNAS.
The group intends to either make or gather a bigger sample to enable more comprehensive analysis and validate whether the signatures from icy moons match the signatures from the freshly discovered hydrates.
Two upcoming objectives will explore Jupiters icy moons: The European Space Agencys Jupiter Icy Moons Explorer mission, releasing in April, and NASAs Europa Clipper objective, introducing for October 2024. NASAs Dragonfly mission introduces to Saturns moon Titan in 2026. Knowing what chemicals these objectives will experience will help to much better target their search for signatures of life.
” These are the only planetary bodies, other than Earth, where liquid water is stable at geological timescales, which is important for the introduction and advancement of life,” Journaux said. “They are, in my opinion, the very best location in our planetary system to find extraterrestrial life, so we need to study their exotic oceans and interiors to better comprehend how they formed, evolved and can retain liquid water in cold areas of the planetary system, up until now far from the sun.”.
Referral: “On the recognition of hyperhydrated sodium chloride hydrates, stable at icy moon conditions” 20 February 2023, Proceedings of the National Academy of Sciences.DOI: 10.1073/ pnas.2217125120.
This research was moneyed by NASA. Co-authors are professor J. Michael Brown and college student Jason Ott at the UW. Additional co-authors were at the German Electron Synchrotron in Hamburg; the European Synchrotron Facility in France; the Institute of Geochemistry and Petrology in Switzerland, the Bavarian Geoinstitute for Experimental Geochemistry and Geophysics in Germany; NASAs Jet Propulsion Laboratory; and the University of Chicago.

One has 2 sodium chlorides for every 17 water particles; the other has one salt chloride for every 13 water particles. Researchers discovered two brand-new crystals made from water and table salt at low temperature levels, listed below about minus 50 C. The recognized structure (left) has one salt particle (yellow and green balls) to two water particles (red and pink balls). The center structure has 2 sodium chloride particles for every 17 water molecules and stays steady even if pressure drops to near vacuum, as would exist on a lunar surface area. The structure on the right has one salt chloride particle for every 13 water molecules, and is stable just at high pressure.