Scientists have managed to recreate a type of ice on Earth that is usually only found on alien worlds, like icy moons and comets.
The type of ice is known as “Ice Seven”, a reference to the structure of its crystalline structure. There are actually 17 different types of ice in total. Bet you didn’t know that, eh? This research was carried out by scientists from Stanford University and published in the journal Physical Review Letters.
While this type of ice has been created before, this time around the researchers were able to find out how it forms so quickly – in billionths of a second. They did this by using the world’s most powerful X-ray laser at the SLAC National Accelerator Laboratory in California.
They fired an intense green laser at a small target that contained a sample of liquid water. This vaporized layers of diamond on one side of the target, which generated a force that compressed the water at a pressure 50,000 times that on Earth’s surface.
A separate beam from the X-ray Free Electron Laser was then fired at the compressed water. This crystallized the water into ice, with the laser firing every one-quadrillionth of a second, into ice VII. It took just six billionths of a second for the water to change into ice VII.
“These are the first studies of this kind were we have an ultrafast X-ray probe combined with a shock driver to access new pressure-temperature-time space for water,” Arianna Gleason, the study’s lead author, told IFLScience.
“The technical advancements needed to complete this study and the advancement of phase transition kinetics theory that will follow from new data of this sort will enable us to design materials with certain desired functional properties.”
In particular, she said seeing a crystalline ice VII structure was exciting. Studying this ice further, which as mentioned is found on alien worlds, could tell us if prebiotic compounds could form here. So next up, the researchers want to use water with a more similar chemistry to icy moons and comets, such as salty water.
“Ice VII is typically thought to exist in the interiors of icy satellites (such as Saturian satellites, Jovian satellites), interiors of ice giant planets, the interiors of large comets and some cometessimals and Trans-Neptunian and Kupier Belt Objects in or near the Oort Cloud,” Gleason added.
