Scientists have discovered a new form of ice through ball milling, which involves shaking frozen water around in a jar of ultracold steel balls. This previously unknown form of amorphous ice is closer to liquid water than any other yet discovered, and it isn’t found naturally on Earth.
What makes this new form of ice so special is that its atoms are not arranged in a neat, crystalline pattern like normal ice. instead, they are disordered and jumbled up. Though amorphous ice is usually low or high density, this new type has a density of 1.06 grams per cubic centimeter.
That makes it incredibly close to the density of water at 1 gram per cubic centimeter. Researchers led by chemist Alexander Rosu-Finsen have named this new form of ice medium-density amorphous ice (or MDA for short).
With MDA accounted for, we now know of at least 20 different crystalline forms of ice, Christoph Salzmann of University College London explained in a statement. Of those twenty types, though, there are only two known forms of amorphous ice currently discovered.
Because of the density gap between normal amorphous ice and this newer type, scientists believe that water, in fact, exists at two very cold temperatures. And, theoretically, we can see both of these liquids exist simultaneously if adjusted to a certain temperature.
This isn’t the only anomaly that has baffled scientists, either. When Amorphous ice was first discovered it left scientists scratching their heads, and when this newest form of ice was presented after a session of ball milling — using balls to grind items down in random patterns — scientists were just as bewildered.
Amorphous ice is only believed to exist in space, and possibly in the highest reaches of the atmosphere. But here on Earth, where temperatures don’t commonly reach the levels needed to form it, this particularly interesting type of ice is a mystery.